Timing advance indication from base station for a beam during handover

ABSTRACT

A method may include sending, by a base station to a wireless device, a radio resource control (RRC) message indicating a handover to a cell. The RRC message can indicate a first timing advance of a first beam of the cell and a second timing advance of a second beam of the cell. The first timing advance and the second timing advance can be provided for beam selection by the wireless device for transmission, via a selected beam of the first beam or the second beam, transport blocks using one of the first timing advance or the second timing advance corresponding to the selected beam.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Pat. Application No.17/495,379, filed Oct. 6, 2021, which is a continuation of U.S. PatentApplication No. 16/866,125, filed May 4, 2020, which claims the benefitof U.S. Provisional Application No. 62/842,473, filed May 2, 2019, allof which are hereby incorporated by reference in their entireties.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosureare described herein with reference to the drawings.

FIG. 1 is a diagram of an example RAN architecture as per an aspect ofan embodiment of the present disclosure.

FIG. 2A is a diagram of an example user plane protocol stack as per anaspect of an embodiment of the present disclosure.

FIG. 2B is a diagram of an example control plane protocol stack as peran aspect of an embodiment of the present disclosure.

FIG. 3 is a diagram of an example wireless device and two base stationsas per an aspect of an embodiment of the present disclosure.

FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D are example diagrams for uplinkand downlink signal transmission as per an aspect of an embodiment ofthe present disclosure.

FIG. 5A is a diagram of an example uplink channel mapping and exampleuplink physical signals as per an aspect of an embodiment of the presentdisclosure.

FIG. 5B is a diagram of an example downlink channel mapping and exampledownlink physical signals as per an aspect of an embodiment of thepresent disclosure.

FIG. 6 is a diagram depicting an example transmission time or receptiontime for a carrier as per an aspect of an embodiment of the presentdisclosure.

FIG. 7A and FIG. 7B are diagrams depicting example sets of OFDMsubcarriers as per an aspect of an embodiment of the present disclosure.

FIG. 8 is a diagram depicting example OFDM radio resources as per anaspect of an embodiment of the present disclosure.

FIG. 9A is a diagram depicting an example CSI-RS and/or SS blocktransmission in a multi-beam system.

FIG. 9B is a diagram depicting an example downlink beam managementprocedure as per an aspect of an embodiment of the present disclosure.

FIG. 10 is an example diagram of configured BWPs as per an aspect of anembodiment of the present disclosure.

FIG. 11A, and FIG. 11B are diagrams of an example multi connectivity asper an aspect of an embodiment of the present disclosure.

FIG. 12 is a diagram of an example random access procedure as per anaspect of an embodiment of the present disclosure.

FIG. 13 is a structure of example MAC entities as per an aspect of anembodiment of the present disclosure.

FIG. 14 is a diagram of an example RAN architecture as per an aspect ofan embodiment of the present disclosure.

FIG. 15 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 16 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 17 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 18 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 19 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 20 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 21 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 22 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 23 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 24 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 25 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 26 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 27 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 28 is a diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 29 is a diagram of an aspect of an example embodiment of thepresent disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments of the present disclosure enable operation ofwireless communication systems. Embodiments of the technology disclosedherein may be employed in the technical field of multicarriercommunication systems. More particularly, the embodiments of thetechnology disclosed herein may relate to radio access networks inmulticarrier communication systems.

The following Acronyms are used throughout the present disclosure:

3GPP 3rd Generation Partnership Project 5GC 5G Core Network ACKAcknowledgement AMF Access and Mobility Management Function ARQAutomatic Repeat Request AS Access Stratum ASIC Application-SpecificIntegrated Circuit BA Bandwidth Adaptation BCCH Broadcast ControlChannel BCH Broadcast Channel BPSK Binary Phase Shift Keying BWPBandwidth Part CA Carrier Aggregation CC Component Carrier CCCH CommonControl CHannel CDMA Code Division Multiple Access CN Core Network CPCyclic Prefix CP-OFDM Cyclic Prefix- Orthogonal Frequency DivisionMultiplex C-RNTI Cell-Radio Network Temporary Identifier CS ConfiguredScheduling CSI Channel State Information CSI-RS Channel StateInformation-Reference Signal CQI Channel Quality Indicator CSS CommonSearch Space CU Central Unit DC Dual Connectivity DCCH Dedicated ControlChannel DCI Downlink Control Information DL Downlink DL-SCH DownlinkShared CHannel DM-RS DeModulation Reference Signal DRB Data Radio BearerDRX Discontinuous Reception DTCH Dedicated Traffic Channel DUDistributed Unit EPC Evolved Packet Core E-UTRA Evolved UMTS TerrestrialRadio Access E-UTRAN Evolved-Universal Terrestrial Radio Access NetworkFDD Frequency Division Duplex FPGA Field Programmable Gate Arrays F1-CF1-Control plane F1-U F1-User plane gNB next generation Node B HARQHybrid Automatic Repeat reQuest HDL Hardware Description Languages IEInformation Element IP Internet Protocol LCID Logical Channel IdentifierLTE Long Term Evolution MAC Media Access Control MCG Master Cell GroupMCS Modulation and Coding Scheme MeNB Master evolved Node B MIB MasterInformation Block MME Mobility Management Entity MN Master Node NACKNegative Acknowledgement NAS Non-Access Stratum NG CP Next GenerationControl Plane NGC Next Generation Core NG-C NG-Control plane ng-eNB nextgeneration evolved Node B NG-U NG-User plane NR New Radio NR MAC NewRadio MAC NR PDCP New Radio PDCP NR PHY New Radio PHYsical NR RLC NewRadio RLC NR RRC New Radio RRC NSSAI Network Slice Selection AssistanceInformation O&M Operation and Maintenance OFDM orthogonal FrequencyDivision Multiplexing PBCH Physical Broadcast CHannel PCC PrimaryComponent Carrier PCCH Paging Control CHannel PCell Primary Cell PCHPaging CHannel PDCCH Physical Downlink Control CHannel PDCP Packet DataConvergence Protocol PDSCH Physical Downlink Shared CHannel PDU ProtocolData Unit PHICH Physical HARQ Indicator CHannel PHY PHYsical PLMN PublicLand Mobile Network PMI Precoding Matrix Indicator PRACH Physical RandomAccess CHannel PRB Physical Resource Block PSCell Primary Secondary CellPSS Primary Synchronization Signal pTAG primary Timing Advance GroupPT-RS Phase Tracking Reference Signal PUCCH Physical Uplink ControlCHannel PUSCH Physical Uplink Shared CHannel QAM Quadrature AmplitudeModulation QFI Quality of Service Indicator QoS Quality of Service QPSKQuadrature Phase Shift Keying RA Random Access RACH Random AccessCHannel RAN Radio Access Network RAT Radio Access Technology RA-RNTIRandom Access-Radio Network Temporary Identifier RB Resource Blocks RBGResource Block Groups RI Rank indicator RLC Radio Link Control RRC RadioResource Control RS Reference Signal RSRP Reference Signal ReceivedPower SCC Secondary Component Carrier SCell Secondary Cell SCG SecondaryCell Group SC-FDMA Single Carrier-Frequency Division Multiple AccessSDAP Service Data Adaptation Protocol SDU Service Data Unit SeNBSecondary evolved Node B SFN System Frame Number S-GW Serving GateWay SISystem Information SIB System Information Block SMF Session ManagementFunction SN Secondary Node SpCell Special Cell SRB Signaling RadioBearer SRS Sounding Reference Signal SS Synchronization Signal SSSSecondary Synchronization Signal sTAG secondary Timing Advance Group TATiming Advance TAG Timing Advance Group TAI Tracking Area Identifier TATTime Alignment Timer TB Transport Block TC-RNTI Temporary Cell-RadioNetwork Temporary Identifier TDD Time Division Duplex TDMA Time DivisionMultiple Access TTI Transmission Time Interval UCI Uplink ControlInformation UE User Equipment UL Uplink UL-SCH Uplink Shared CHannel UPFUser Plane Function UPGW User Plane Gateway VHDL VHSIC HardwareDescription Language Xn-C Xn-Control plane Xn-U Xn-User plane

Example embodiments of the disclosure may be implemented using variousphysical layer modulation and transmission mechanisms. Exampletransmission mechanisms may include, but are not limited to: CodeDivision Multiple Access (CDMA), Orthogonal Frequency Division MultipleAccess (OFDMA), Time Division Multiple Access (TDMA), Wavelettechnologies, and/or the like. Hybrid transmission mechanisms such asTDMA/CDMA, and OFDM/CDMA may also be employed. Various modulationschemes may be applied for signal transmission in the physical layer.Examples of modulation schemes include, but are not limited to: phase,amplitude, code, a combination of these, and/or the like. An exampleradio transmission method may implement Quadrature Amplitude Modulation(QAM) using Binary Phase Shift Keying (BPSK), Quadrature Phase ShiftKeying (QPSK), 16-QAM, 64-QAM, 256-QAM, and/or the like. Physical radiotransmission may be enhanced by dynamically or semi-dynamically changingthe modulation and coding scheme depending on transmission requirementsand radio conditions.

FIG. 1 is an example Radio Access Network (RAN) architecture as per anaspect of an embodiment of the present disclosure. As illustrated inthis example, a RAN node may be a next generation Node B (gNB) (e.g.120A, 120B) providing New Radio (NR) user plane and control planeprotocol terminations towards a first wireless device (e.g. 110A). In anexample, a RAN node may be a next generation evolved Node B (ng-eNB)(e.g. 120C, 120D), providing Evolved UMTS Terrestrial Radio Access(E-UTRA) user plane and control plane protocol terminations towards asecond wireless device (e.g. 110B). The first wireless device maycommunicate with a gNB over a Uu interface. The second wireless devicemay communicate with a ng-eNB over a Uu interface.

A gNB or an ng-eNB may host functions such as radio resource managementand scheduling, IP header compression, encryption and integrityprotection of data, selection of Access and Mobility Management Function(AMF) at User Equipment (UE) attachment, routing of user plane andcontrol plane data, connection setup and release, scheduling andtransmission of paging messages (originated from the AMF), schedulingand transmission of system broadcast information (originated from theAMF or Operation and Maintenance (O&M)), measurement and measurementreporting configuration, transport level packet marking in the uplink,session management, support of network slicing, Quality of Service (QoS)flow management and mapping to data radio bearers, support of UEs inRRC_INACTIVE state, distribution function for Non-Access Stratum (NAS)messages, RAN sharing, dual connectivity or tight interworking betweenNR and E-UTRA.

In an example, one or more gNBs and/or one or more ng-eNBs may beinterconnected with each other by means of Xn interface. A gNB or anng-eNB may be connected by means of NG interfaces to 5G Core Network(5GC). In an example, 5GC may comprise one or more AMF/User PlanFunction (UPF) functions (e.g. 130A or 130B). A gNB or an ng-eNB may beconnected to a UPF by means of an NG-User plane (NG-U) interface. TheNG-U interface may provide delivery (e.g. non-guaranteed delivery) ofuser plane Protocol Data Units (PDUs) between a RAN node and the UPF. AgNB or an ng-eNB may be connected to an AMF by means of an NG-Controlplane (NG-C) interface. The NG-C interface may provide functions such asNG interface management, UE context management, UE mobility management,transport of NAS messages, paging, PDU session management, configurationtransfer or warning message transmission.

In an example, a UPF may host functions such as anchor point forintra-/inter-Radio Access Technology (RAT) mobility (when applicable),external PDU session point of interconnect to data network, packetrouting and forwarding, packet inspection and user plane part of policyrule enforcement, traffic usage reporting, uplink classifier to supportrouting traffic flows to a data network, branching point to supportmulti-homed PDU session, QoS handling for user plane, e.g. packetfiltering, gating, Uplink (UL)/Downlink (DL) rate enforcement, uplinktraffic verification (e.g. Service Data Flow (SDF) to QoS flow mapping),downlink packet buffering and/or downlink data notification triggering.

In an example, an AMF may host functions such as NAS signalingtermination, NAS signaling security, Access Stratum (AS) securitycontrol, inter Core Network (CN) node signaling for mobility between3^(rd) Generation Partnership Project (3GPP) access networks, idle modeUE reachability (e.g., control and execution of paging retransmission),registration area management, support of intra-system and inter-systemmobility, access authentication, access authorization including check ofroaming rights, mobility management control (subscription and policies),support of network slicing and/or Session Management Function (SMF)selection.

FIG. 2A is an example user plane protocol stack, where Service DataAdaptation Protocol (SDAP) (e.g. 211 and 221), Packet Data ConvergenceProtocol (PDCP) (e.g. 212 and 222), Radio Link Control (RLC) (e.g. 213and 223) and Media Access Control (MAC) (e.g. 214 and 224) sublayers andPhysical (PHY) (e.g. 215 and 225) layer may be terminated in wirelessdevice (e.g. 110) and gNB (e.g. 120) on the network side. In an example,a PHY layer provides transport services to higher layers (e.g. MAC, RRC,etc). In an example, services and functions of a MAC sublayer maycomprise mapping between logical channels and transport channels,multiplexing/demultiplexing of MAC Service Data Units (SDUs) belongingto one or different logical channels into/from Transport Blocks (TBs)delivered to/from the PHY layer, scheduling information reporting, errorcorrection through Hybrid Automatic Repeat request (HARQ) (e.g. one HARQentity per carrier in case of Carrier Aggregation (CA)), priorityhandling between UEs by means of dynamic scheduling, priority handlingbetween logical channels of one UE by means of logical channelprioritization, and/or padding. A MAC entity may support one or multiplenumerologies and/or transmission timings. In an example, mappingrestrictions in a logical channel prioritization may control whichnumerology and/or transmission timing a logical channel may use. In anexample, an RLC sublayer may supports transparent mode (TM),unacknowledged mode (UM) and acknowledged mode (AM) transmission modes.The RLC configuration may be per logical channel with no dependency onnumerologies and/or Transmission Time Interval (TTI) durations. In anexample, Automatic Repeat Request (ARQ) may operate on any of thenumerologies and/or TTI durations the logical channel is configuredwith. In an example, services and functions of the PDCP layer for theuser plane may comprise sequence numbering, header compression anddecompression, transfer of user data, reordering and duplicatedetection, PDCP PDU routing (e.g. in case of split bearers),retransmission of PDCP SDUs, ciphering, deciphering and integrityprotection, PDCP SDU discard, PDCP reestablishment and data recovery forRLC AM, and/or duplication of PDCP PDUs. In an example, services andfunctions of SDAP may comprise mapping between a QoS flow and a dataradio bearer. In an example, services and functions of SDAP may comprisemapping Quality of Service Indicator (QFI) in DL and UL packets. In anexample, a protocol entity of SDAP may be configured for an individualPDU session.

FIG. 2B is an example control plane protocol stack where PDCP (e.g. 233and 242), RLC (e.g. 234 and 243) and MAC (e.g. 235 and 244) sublayersand PHY (e.g. 236 and 245) layer may be terminated in wireless device(e.g. 110) and gNB (e.g. 120) on a network side and perform service andfunctions described above. In an example, RRC (e.g. 232 and 241) may beterminated in a wireless device and a gNB on a network side. In anexample, services and functions of RRC may comprise broadcast of systeminformation related to AS and NAS, paging initiated by 5GC or RAN,establishment, maintenance and release of an RRC connection between theUE and RAN, security functions including key management, establishment,configuration, maintenance and release of Signaling Radio Bearers (SRBs)and Data Radio Bearers (DRBs), mobility functions, QoS managementfunctions, UE measurement reporting and control of the reporting,detection of and recovery from radio link failure, and/or NAS messagetransfer to/from NAS from/to a UE. In an example, NAS control protocol(e.g. 231 and 251) may be terminated in the wireless device and AMF(e.g. 130) on a network side and may perform functions such asauthentication, mobility management between a UE and a AMF for 3GPPaccess and non-3GPP access, and session management between a UE and aSMF for 3GPP access and non-3GPP access.

In an example, a base station may configure a plurality of logicalchannels for a wireless device. A logical channel in the plurality oflogical channels may correspond to a radio bearer and the radio bearermay be associated with a QoS requirement. In an example, a base stationmay configure a logical channel to be mapped to one or moreTTIs/numerologies in a plurality of TTIs/numerologies. The wirelessdevice may receive a Downlink Control Information (DCI) via PhysicalDownlink Control CHannel (PDCCH) indicating an uplink grant. In anexample, the uplink grant may be for a first TTI/numerology and mayindicate uplink resources for transmission of a transport block. Thebase station may configure each logical channel in the plurality oflogical channels with one or more parameters to be used by a logicalchannel prioritization procedure at the MAC layer of the wirelessdevice. The one or more parameters may comprise priority, prioritizedbit rate, etc. A logical channel in the plurality of logical channelsmay correspond to one or more buffers comprising data associated withthe logical channel. The logical channel prioritization procedure mayallocate the uplink resources to one or more first logical channels inthe plurality of logical channels and/or one or more MAC ControlElements (CEs). The one or more first logical channels may be mapped tothe first TTI/numerology. The MAC layer at the wireless device maymultiplex one or more MAC CEs and/or one or more MAC SDUs (e.g., logicalchannel) in a MAC PDU (e.g., transport block). In an example, the MACPDU may comprise a MAC header comprising a plurality of MAC sub-headers.A MAC sub-header in the plurality of MAC sub-headers may correspond to aMAC CE or a MAC SUD (logical channel) in the one or more MAC CEs and/orone or more MAC SDUs. In an example, a MAC CE or a logical channel maybe configured with a Logical Channel IDentifier (LCID). In an example,LCID for a logical channel or a MAC CE may be fixed/pre-configured. Inan example, LCID for a logical channel or MAC CE may be configured forthe wireless device by the base station. The MAC sub-headercorresponding to a MAC CE or a MAC SDU may comprise LCID associated withthe MAC CE or the MAC SDU.

In an example, a base station may activate and/or deactivate and/orimpact one or more processes (e.g., set values of one or more parametersof the one or more processes or start and/or stop one or more timers ofthe one or more processes) at the wireless device by employing one ormore MAC commands. The one or more MAC commands may comprise one or moreMAC control elements. In an example, the one or more processes maycomprise activation and/or deactivation of PDCP packet duplication forone or more radio bearers. The base station may transmit a MAC CEcomprising one or more fields, the values of the fields indicatingactivation and/or deactivation of PDCP duplication for the one or moreradio bearers. In an example, the one or more processes may compriseChannel State Information (CSI) transmission of on one or more cells.The base station may transmit one or more MAC CEs indicating activationand/or deactivation of the CSI transmission on the one or more cells. Inan example, the one or more processes may comprise activation ordeactivation of one or more secondary cells. In an example, the basestation may transmit a MA CE indicating activation or deactivation ofone or more secondary cells. In an example, the base station maytransmit one or more MAC CEs indicating starting and/or stopping one ormore Discontinuous Reception (DRX) timers at the wireless device. In anexample, the base station may transmit one or more MAC CEs indicatingone or more timing advance values for one or more Timing Advance Groups(TAGs).

FIG. 3 is a block diagram of base stations (base station 1, 120A, andbase station 2, 120B) and a wireless device 110. A wireless device maybe called an UE. A base station may be called a NB, eNB, gNB, and/orng-eNB. In an example, a wireless device and/or a base station may actas a relay node. The base station 1, 120A, may comprise at least onecommunication interface 320A (e.g. a wireless modem, an antenna, a wiredmodem, and/or the like), at least one processor 321A, and at least oneset of program code instructions 323A stored in non-transitory memory322A and executable by the at least one processor 321A. The base station2, 120B, may comprise at least one communication interface 320B, atleast one processor 321B, and at least one set of program codeinstructions 323B stored in non-transitory memory 322B and executable bythe at least one processor 321B.

A base station may comprise many sectors for example: 1, 2, 3, 4, or 6sectors. A base station may comprise many cells, for example, rangingfrom 1 to 50 cells or more. A cell may be categorized, for example, as aprimary cell or secondary cell. At Radio Resource Control (RRC)connection establishment/re-establishment/handover, one serving cell mayprovide the NAS (non-access stratum) mobility information (e.g. TrackingArea Identifier (TAI)). At RRC connection re-establishment/handover, oneserving cell may provide the security input. This cell may be referredto as the Primary Cell (PCell). In the downlink, a carrier correspondingto the PCell may be a DL Primary Component Carrier (PCC), while in theuplink, a carrier may be an UL PCC. Depending on wireless devicecapabilities, Secondary Cells (SCells) may be configured to formtogether with a PCell a set of serving cells. In a downlink, a carriercorresponding to an SCell may be a downlink secondary component carrier(DL SCC), while in an uplink, a carrier may be an uplink secondarycomponent carrier (UL SCC). An SCell may or may not have an uplinkcarrier.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned a physical cell ID and a cell index. A carrier (downlinkor uplink) may belong to one cell. The cell ID or cell index may alsoidentify the downlink carrier or uplink carrier of the cell (dependingon the context it is used). In the disclosure, a cell ID may be equallyreferred to a carrier ID, and a cell index may be referred to a carrierindex. In an implementation, a physical cell ID or a cell index may beassigned to a cell. A cell ID may be determined using a synchronizationsignal transmitted on a downlink carrier. A cell index may be determinedusing RRC messages. For example, when the disclosure refers to a firstphysical cell ID for a first downlink carrier, the disclosure may meanthe first physical cell ID is for a cell comprising the first downlinkcarrier. The same concept may apply to, for example, carrier activation.When the disclosure indicates that a first carrier is activated, thespecification may equally mean that a cell comprising the first carrieris activated.

A base station may transmit to a wireless device one or more messages(e.g. RRC messages) comprising a plurality of configuration parametersfor one or more cells. One or more cells may comprise at least oneprimary cell and at least one secondary cell. In an example, an RRCmessage may be broadcasted or unicasted to the wireless device. In anexample, configuration parameters may comprise common parameters anddedicated parameters.

Services and/or functions of an RRC sublayer may comprise at least oneof: broadcast of system information related to AS and NAS; paginginitiated by 5GC and/or NG-RAN; establishment, maintenance, and/orrelease of an RRC connection between a wireless device and NG-RAN, whichmay comprise at least one of addition, modification and release ofcarrier aggregation; or addition, modification, and/or release of dualconnectivity in NR or between E-UTRA and NR. Services and/or functionsof an RRC sublayer may further comprise at least one of securityfunctions comprising key management; establishment, configuration,maintenance, and/or release of Signaling Radio Bearers (SRBs) and/orData Radio Bearers (DRBs); mobility functions which may comprise atleast one of a handover (e.g. intra NR mobility or inter-RAT mobility)and a context transfer; or a wireless device cell selection andreselection and control of cell selection and reselection. Servicesand/or functions of an RRC sublayer may further comprise at least one ofQoS management functions; a wireless device measurementconfiguration/reporting; detection of and/or recovery from radio linkfailure; or NAS message transfer to/from a core network entity (e.g.AMF, Mobility Management Entity (MME)) from/to the wireless device.

An RRC sublayer may support an RRC_Idle state, an RRC_Inactive stateand/or an RRC_Connected state for a wireless device. In an RRC_Idlestate, a wireless device may perform at least one of: Public Land MobileNetwork (PLMN) selection; receiving broadcasted system information; cellselection/re-selection; monitoring/receiving a paging for mobileterminated data initiated by 5GC; paging for mobile terminated data areamanaged by 5GC; or DRX for CN paging configured via NAS. In anRRC_Inactive state, a wireless device may perform at least one of:receiving broadcasted system information; cell selection/re-selection;monitoring/receiving a RAN/CN paging initiated by NG-RAN/5GC; RAN-basednotification area (RNA) managed by NG- RAN; or DRX for RAN/CN pagingconfigured by NG-RAN/NAS. In an RRC_Idle state of a wireless device, abase station (e.g. NG-RAN) may keep a 5GC-NG-RAN connection (bothC/U-planes) for the wireless device; and/or store a UE AS context forthe wireless device. In an RRC_Connected state of a wireless device, abase station (e.g. NG-RAN) may perform at least one of: establishment of5GC-NG-RAN connection (both C/U-planes) for the wireless device; storinga UE AS context for the wireless device; transmit/receive of unicastdata to/from the wireless device; or network-controlled mobility basedon measurement results received from the wireless device. In anRRC_Connected state of a wireless device, an NG-RAN may know a cell thatthe wireless device belongs to.

System information (SI) may be divided into minimum SI and other SI. Theminimum SI may be periodically broadcast. The minimum SI may comprisebasic information required for initial access and information foracquiring any other SI broadcast periodically or provisioned on-demand,i.e. scheduling information. The other SI may either be broadcast, or beprovisioned in a dedicated manner, either triggered by a network or uponrequest from a wireless device. A minimum SI may be transmitted via twodifferent downlink channels using different messages (e.g.MasterInformationBlock and SystemInformationBlockType1). An other SI maybe transmitted via SystemInformationBlockType2. For a wireless device inan RRC_Connected state, dedicated RRC signalling may be employed for therequest and delivery of the other SI. For the wireless device in theRRC_Idle state and/or the RRC_Inactive state, the request may trigger arandom-access procedure.

A wireless device may report its radio access capability informationwhich may be static. A base station may request what capabilities for awireless device to report based on band information. When allowed by anetwork, a temporary capability restriction request may be sent by thewireless device to signal the limited availability of some capabilities(e.g. due to hardware sharing, interference or overheating) to the basestation. The base station may confirm or reject the request. Thetemporary capability restriction may be transparent to 5GC (e.g., onlystatic capabilities may be stored in 5GC).

When CA is configured, a wireless device may have an RRC connection witha network. At RRC connection establishment/re-establishment/handoverprocedure, one serving cell may provide NAS mobility information, and atRRC connection re-establishment/handover, one serving cell may provide asecurity input. This cell may be referred to as the PCell. Depending onthe capabilities of the wireless device, SCells may be configured toform together with the PCell a set of serving cells. The configured setof serving cells for the wireless device may comprise one PCell and oneor more SCells.

The reconfiguration, addition and removal of SCells may be performed byRRC. At intra-NR handover, RRC may also add, remove, or reconfigureSCells for usage with the target PCell. When adding a new SCell,dedicated RRC signalling may be employed to send all required systeminformation of the SCell i.e. while in connected mode, wireless devicesmay not need to acquire broadcasted system information directly from theSCells.

The purpose of an RRC connection reconfiguration procedure may be tomodify an RRC connection, (e.g. to establish, modify and/or release RBs,to perform handover, to setup, modify, and/or release measurements, toadd, modify, and/or release SCells and cell groups). As part of the RRCconnection reconfiguration procedure, NAS dedicated information may betransferred from the network to the wireless device. TheRRCConnectionReconfiguration message may be a command to modify an RRCconnection. It may convey information for measurement configuration,mobility control, radio resource configuration (e.g. RBs, MAC mainconfiguration and physical channel configuration) comprising anyassociated dedicated NAS information and security configuration. If thereceived RRC Connection Reconfiguration message includes thesCellToReleaseList, the wireless device may perform an SCell release. Ifthe received RRC Connection Reconfiguration message includes thesCellToAddModList, the wireless device may perform SCell additions ormodification.

An RRC connection establishment (or reestablishment, resume) proceduremay be to establish (or reestablish, resume) an RRC connection. an RRCconnection establishment procedure may comprise SRB1 establishment. TheRRC connection establishment procedure may be used to transfer theinitial NAS dedicated information/ message from a wireless device toE-UTRAN. The RRCConnectionReestablishment message may be used tore-establish SRB1.

A measurement report procedure may be to transfer measurement resultsfrom a wireless device to NG-RAN. The wireless device may initiate ameasurement report procedure after successful security activation. Ameasurement report message may be employed to transmit measurementresults.

The wireless device 110 may comprise at least one communicationinterface 310 (e.g. a wireless modem, an antenna, and/or the like), atleast one processor 314, and at least one set of program codeinstructions 316 stored in non-transitory memory 315 and executable bythe at least one processor 314. The wireless device 110 may furthercomprise at least one of at least one speaker/microphone 311, at leastone keypad 312, at least one display/touchpad 313, at least one powersource 317, at least one global positioning system (GPS) chipset 318,and other peripherals 319.

The processor 314 of the wireless device 110, the processor 321A of thebase station 1 120A, and/or the processor 321B of the base station 2120B may comprise at least one of a general-purpose processor, a digitalsignal processor (DSP), a controller, a microcontroller, an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA) and/or other programmable logic device, discrete gate and/ortransistor logic, discrete hardware components, and the like. Theprocessor 314 of the wireless device 110, the processor 321A in basestation 1 120A, and/or the processor 321B in base station 2 120B mayperform at least one of signal coding/processing, data processing, powercontrol, input/output processing, and/or any other functionality thatmay enable the wireless device 110, the base station 1 120A and/or thebase station 2 120B to operate in a wireless environment.

The processor 314 of the wireless device 110 may be connected to thespeaker/microphone 311, the keypad 312, and/or the display/touchpad 313.The processor 314 may receive user input data from and/or provide useroutput data to the speaker/microphone 311, the keypad 312, and/or thedisplay/touchpad 313. The processor 314 in the wireless device 110 mayreceive power from the power source 317 and/or may be configured todistribute the power to the other components in the wireless device 110.The power source 317 may comprise at least one of one or more dry cellbatteries, solar cells, fuel cells, and the like. The processor 314 maybe connected to the GPS chipset 318. The GPS chipset 318 may beconfigured to provide geographic location information of the wirelessdevice 110.

The processor 314 of the wireless device 110 may further be connected toother peripherals 319, which may comprise one or more software and/orhardware modules that provide additional features and/orfunctionalities. For example, the peripherals 319 may comprise at leastone of an accelerometer, a satellite transceiver, a digital camera, auniversal serial bus (USB) port, a hands-free headset, a frequencymodulated (FM) radio unit, a media player, an Internet browser, and thelike.

The communication interface 320A of the base station 1, 120A, and/or thecommunication interface 320B of the base station 2, 120B, may beconfigured to communicate with the communication interface 310 of thewireless device 110 via a wireless link 330A and/or a wireless link 330Brespectively. In an example, the communication interface 320A of thebase station 1, 120A, may communicate with the communication interface320B of the base station 2 and other RAN and core network nodes.

The wireless link 330A and/or the wireless link 330B may comprise atleast one of a bidirectional link and/or a directional link. Thecommunication interface 310 of the wireless device 110 may be configuredto communicate with the communication interface 320A of the base station1 120A and/or with the communication interface 320B of the base station2 120B. The base station 1 120A and the wireless device 110 and/or thebase station 2 120B and the wireless device 110 may be configured tosend and receive transport blocks via the wireless link 330A and/or viathe wireless link 330B, respectively. The wireless link 330A and/or thewireless link 330B may employ at least one frequency carrier. Accordingto some of various aspects of embodiments, transceiver(s) may beemployed. A transceiver may be a device that comprises both atransmitter and a receiver. Transceivers may be employed in devices suchas wireless devices, base stations, relay nodes, and/or the like.Example embodiments for radio technology implemented in thecommunication interface 310, 320A, 320B and the wireless link 330A, 330Bare illustrated in FIG. 4A, FIG. 4B, FIG. 4C, FIG. 4D, FIG. 6 , FIG. 7A,FIG. 7B, FIG. 8 , and associated text.

In an example, other nodes in a wireless network (e.g. AMF, UPF, SMF,etc) may comprise one or more communication interfaces, one or moreprocessors, and memory storing instructions.

A node (e.g. wireless device, base station, AMF, SMF, UPF, servers,switches, antennas, and/or the like) may comprise one or moreprocessors, and memory storing instructions that when executed by theone or more processors causes the node to perform certain processesand/or functions. Example embodiments may enable operation ofsingle-carrier and/or multi-carrier communications. Other exampleembodiments may comprise a non-transitory tangible computer readablemedia comprising instructions executable by one or more processors tocause operation of single-carrier and/or multi-carrier communications.Yet other example embodiments may comprise an article of manufacturethat comprises a non-transitory tangible computer readablemachine-accessible medium having instructions encoded thereon forenabling programmable hardware to cause a node to enable operation ofsingle-carrier and/or multi-carrier communications. The node may includeprocessors, memory, interfaces, and/or the like.

An interface may comprise at least one of a hardware interface, afirmware interface, a software interface, and/or a combination thereof.The hardware interface may comprise connectors, wires, electronicdevices such as drivers, amplifiers, and/or the like. The softwareinterface may comprise code stored in a memory device to implementprotocol(s), protocol layers, communication drivers, device drivers,combinations thereof, and/or the like. The firmware interface maycomprise a combination of embedded hardware and code stored in and/or incommunication with a memory device to implement connections, electronicdevice operations, protocol(s), protocol layers, communication drivers,device drivers, hardware operations, combinations thereof, and/or thelike.

FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D are example diagrams for uplinkand downlink signal transmission as per an aspect of an embodiment ofthe present disclosure. FIG. 4A shows an example uplink transmitter forat least one physical channel. A baseband signal representing a physicaluplink shared channel may perform one or more functions. The one or morefunctions may comprise at least one of: scrambling; modulation ofscrambled bits to generate complex-valued symbols; mapping of thecomplex-valued modulation symbols onto one or several transmissionlayers; transform precoding to generate complex-valued symbols;precoding of the complex-valued symbols; mapping of precodedcomplex-valued symbols to resource elements; generation ofcomplex-valued time-domain Single Carrier-Frequency Division MultipleAccess (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like.In an example, when transform precoding is enabled, a SC-FDMA signal foruplink transmission may be generated. In an example, when transformprecoding is not enabled, an CP-OFDM signal for uplink transmission maybe generated by FIG. 4A. These functions are illustrated as examples andit is anticipated that other mechanisms may be implemented in variousembodiments.

An example structure for modulation and up-conversion to the carrierfrequency of the complex-valued SC-FDMA or CP-OFDM baseband signal foran antenna port and/or the complex-valued Physical Random Access CHannel(PRACH) baseband signal is shown in FIG. 4B. Filtering may be employedprior to transmission.

An example structure for downlink transmissions is shown in FIG. 4C. Thebaseband signal representing a downlink physical channel may perform oneor more functions. The one or more functions may comprise: scrambling ofcoded bits in a codeword to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on a layer for transmission on the antenna ports; mapping ofcomplex-valued modulation symbols for an antenna port to resourceelements; generation of complex-valued time-domain OFDM signal for anantenna port; and/or the like. These functions are illustrated asexamples and it is anticipated that other mechanisms may be implementedin various embodiments.

In an example, a gNB may transmit a first symbol and a second symbol onan antenna port, to a wireless device. The wireless device may infer thechannel (e.g., fading gain, multipath delay, etc.) for conveying thesecond symbol on the antenna port, from the channel for conveying thefirst symbol on the antenna port. In an example, a first antenna portand a second antenna port may be quasi co-located if one or morelarge-scale properties of the channel over which a first symbol on thefirst antenna port is conveyed may be inferred from the channel overwhich a second symbol on a second antenna port is conveyed. The one ormore large-scale properties may comprise at least one of: delay spread;doppler spread; doppler shift; average gain; average delay; and/orspatial Receiving (Rx) parameters.

An example modulation and up-conversion to the carrier frequency of thecomplex-valued OFDM baseband signal for an antenna port is shown in FIG.4D. Filtering may be employed prior to transmission.

FIG. 5A is a diagram of an example uplink channel mapping and exampleuplink physical signals. FIG. 5B is a diagram of an example downlinkchannel mapping and a downlink physical signals. In an example, aphysical layer may provide one or more information transfer services toa MAC and/or one or more higher layers. For example, the physical layermay provide the one or more information transfer services to the MAC viaone or more transport channels. An information transfer service mayindicate how and with what characteristics data are transferred over theradio interface.

In an example embodiment, a radio network may comprise one or moredownlink and/or uplink transport channels. For example, a diagram inFIG. 5A shows example uplink transport channels comprising Uplink-SharedCHannel (UL-SCH) 501 and Random Access CHannel (RACH) 502. A diagram inFIG. 5B shows example downlink transport channels comprisingDownlink-Shared CHannel (DL-SCH) 511, Paging CHannel (PCH) 512, andBroadcast CHannel (BCH) 513. A transport channel may be mapped to one ormore corresponding physical channels. For example, UL-SCH 501 may bemapped to Physical Uplink Shared CHannel (PUSCH) 503. RACH 502 may bemapped to PRACH 505. DL-SCH 511 and PCH 512 may be mapped to PhysicalDownlink Shared CHannel (PDSCH) 514. BCH 513 may be mapped to PhysicalBroadcast CHannel (PBCH) 516.

There may be one or more physical channels without a correspondingtransport channel. The one or more physical channels may be employed forUplink Control Information (UCI) 509 and/or Downlink Control Information(DCI) 517. For example, Physical Uplink Control CHannel (PUCCH) 504 maycarry UCI 509 from a UE to a base station. For example, PhysicalDownlink Control CHannel (PDCCH) 515 may carry DCI 517 from a basestation to a UE. NR may support UCI 509 multiplexing in PUSCH 503 whenUCI 509 and PUSCH 503 transmissions may coincide in a slot at least inpart. The UCI 509 may comprise at least one of CSI, Acknowledgement(ACK)/Negative Acknowledgement (NACK), and/or scheduling request. TheDCI 517 on PDCCH 515 may indicate at least one of following: one or moredownlink assignments and/or one or more uplink scheduling grants

In uplink, a UE may transmit one or more Reference Signals (RSs) to abase station. For example, the one or more RSs may be at least one ofDemodulation-RS (DM-RS) 506, Phase Tracking-RS (PT-RS) 507, and/orSounding RS (SRS) 508. In downlink, a base station may transmit (e.g.,unicast, multicast, and/or broadcast) one or more RSs to a UE. Forexample, the one or more RSs may be at least one of PrimarySynchronization Signal (PSS)/Secondary Synchronization Signal (SSS) 521,CSI-RS 522, DM-RS 523, and/or PT-RS 524.

In an example, a UE may transmit one or more uplink DM-RSs 506 to a basestation for channel estimation, for example, for coherent demodulationof one or more uplink physical channels (e.g., PUSCH 503 and/or PUCCH504). For example, a UE may transmit a base station at least one uplinkDM-RS 506 with PUSCH 503 and/or PUCCH 504, wherein the at least oneuplink DM-RS 506 may be spanning a same frequency range as acorresponding physical channel. In an example, a base station mayconfigure a UE with one or more uplink DM-RS configurations. At leastone DM-RS configuration may support a front-loaded DM-RS pattern. Afront-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1or 2 adjacent OFDM symbols). One or more additional uplink DM-RS may beconfigured to transmit at one or more symbols of a PUSCH and/or PUCCH. Abase station may semi-statistically configure a UE with a maximum numberof front-loaded DM-RS symbols for PUSCH and/or PUCCH. For example, a UEmay schedule a single-symbol DM-RS and/or double symbol DM-RS based on amaximum number of front-loaded DM-RS symbols, wherein a base station mayconfigure the UE with one or more additional uplink DM-RS for PUSCHand/or PUCCH. A new radio network may support, e.g., at least forCP-OFDM, a common DM-RS structure for DL and UL, wherein a DM-RSlocation, DM-RS pattern, and/or scrambling sequence may be same ordifferent.

In an example, whether uplink PT-RS 507 is present or not may depend ona RRC configuration. For example, a presence of uplink PT-RS may beUE-specifically configured. For example, a presence and/or a pattern ofuplink PT-RS 507 in a scheduled resource may be UE-specificallyconfigured by a combination of RRC signaling and/or association with oneor more parameters employed for other purposes (e.g., Modulation andCoding Scheme (MCS)) which may be indicated by DCI. When configured, adynamic presence of uplink PT-RS 507 may be associated with one or moreDCI parameters comprising at least MCS. A radio network may supportplurality of uplink PT-RS densities defined in time/frequency domain.When present, a frequency domain density may be associated with at leastone configuration of a scheduled bandwidth. A UE may assume a sameprecoding for a DMRS port and a PT-RS port. A number of PT-RS ports maybe fewer than a number of DM-RS ports in a scheduled resource. Forexample, uplink PT-RS 507 may be confined in the scheduledtime/frequency duration for a UE.

In an example, a UE may transmit SRS 508 to a base station for channelstate estimation to support uplink channel dependent scheduling and/orlink adaptation. For example, SRS 508 transmitted by a UE may allow fora base station to estimate an uplink channel state at one or moredifferent frequencies. A base station scheduler may employ an uplinkchannel state to assign one or more resource blocks of good quality foran uplink PUSCH transmission from a UE. A base station maysemi-statistically configure a UE with one or more SRS resource sets.For an SRS resource set, a base station may configure a UE with one ormore SRS resources. An SRS resource set applicability may be configuredby a higher layer (e.g., RRC) parameter. For example, when a higherlayer parameter indicates beam management, a SRS resource in each of oneor more SRS resource sets may be transmitted at a time instant. A UE maytransmit one or more SRS resources in different SRS resource setssimultaneously. A new radio network may support aperiodic, periodicand/or semi-persistent SRS transmissions. A UE may transmit SRSresources based on one or more trigger types, wherein the one or moretrigger types may comprise higher layer signaling (e.g., RRC) and/or oneor more DCI formats (e.g., at least one DCI format may be employed for aUE to select at least one of one or more configured SRS resource sets.An SRS trigger type 0 may refer to an SRS triggered based on a higherlayer signaling. An SRS trigger type 1 may refer to an SRS triggeredbased on one or more DCI formats. In an example, when PUSCH 503 and SRS508 are transmitted in a same slot, a UE may be configured to transmitSRS 508 after a transmission of PUSCH 503 and corresponding uplink DM-RS506.

In an example, a base station may semi-statistically configure a UE withone or more SRS configuration parameters indicating at least one offollowing: a SRS resource configuration identifier, a number of SRSports, time domain behavior of SRS resource configuration (e.g., anindication of periodic, semi-persistent, or aperiodic SRS), slot(mini-slot, and/or subframe) level periodicity and/or offset for aperiodic and/or aperiodic SRS resource, a number of OFDM symbols in aSRS resource, starting OFDM symbol of a SRS resource, a SRS bandwidth, afrequency hopping bandwidth, a cyclic shift, and/or a SRS sequence ID.

In an example, in a time domain, an SS/PBCH block may comprise one ormore OFDM symbols (e.g., 4 OFDM symbols numbered in increasing orderfrom 0 to 3) within the SS/PBCH block. An SS/PBCH block may comprisePSS/SSS 521 and PBCH 516. In an example, in the frequency domain, anSS/PBCH block may comprise one or more contiguous subcarriers (e.g., 240contiguous subcarriers with the subcarriers numbered in increasing orderfrom 0 to 239) within the SS/PBCH block. For example, a PSS/SSS 521 mayoccupy 1 OFDM symbol and 127 subcarriers. For example, PBCH 516 may spanacross 3 OFDM symbols and 240 subcarriers. A UE may assume that one ormore SS/PBCH blocks transmitted with a same block index may be quasico-located, e.g., with respect to Doppler spread, Doppler shift, averagegain, average delay, and spatial Rx parameters. A UE may not assumequasi co-location for other SS/PBCH block transmissions. A periodicityof an SS/PBCH block may be configured by a radio network (e.g., by anRRC signaling) and one or more time locations where the SS/PBCH blockmay be sent may be determined by sub-carrier spacing. In an example, aUE may assume a band-specific sub-carrier spacing for an SS/PBCH blockunless a radio network has configured a UE to assume a differentsub-carrier spacing.

In an example, downlink CSI-RS 522 may be employed for a UE to acquirechannel state information. A radio network may support periodic,aperiodic, and/or semi-persistent transmission of downlink CSI-RS 522.For example, a base station may semi-statistically configure and/orreconfigure a UE with periodic transmission of downlink CSI-RS 522. Aconfigured CSI-RS resources may be activated ad/or deactivated. Forsemi-persistent transmission, an activation and/or deactivation ofCSI-RS resource may be triggered dynamically. In an example, CSI-RSconfiguration may comprise one or more parameters indicating at least anumber of antenna ports. For example, a base station may configure a UEwith 32 ports. A base station may semi-statistically configure a UE withone or more CSI-RS resource sets. One or more CSI-RS resources may beallocated from one or more CSI-RS resource sets to one or more UEs. Forexample, a base station may semi-statistically configure one or moreparameters indicating CSI RS resource mapping, for example, time-domainlocation of one or more CSI-RS resources, a bandwidth of a CSI-RSresource, and/or a periodicity. In an example, a UE may be configured toemploy a same OFDM symbols for downlink CSI-RS 522 and Control ResourceSet (CORESET) when the downlink CSI-RS 522 and CORESET are spatiallyquasi co-located and resource elements associated with the downlinkCSI-RS 522 are the outside of PRBs configured for CORESET. In anexample, a UE may be configured to employ a same OFDM symbols fordownlink CSI-RS 522 and SSB/PBCH when the downlink CSI-RS 522 andSSB/PBCH are spatially quasi co-located and resource elements associatedwith the downlink CSI-RS 522 are the outside of PRBs configured forSSB/PBCH.

In an example, a UE may transmit one or more downlink DM-RSs 523 to abase station for channel estimation, for example, for coherentdemodulation of one or more downlink physical channels (e.g., PDSCH514). For example, a radio network may support one or more variableand/or configurable DM-RS patterns for data demodulation. At least onedownlink DM-RS configuration may support a front-loaded DM-RS pattern. Afront-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1or 2 adjacent OFDM symbols). A base station may semi-statisticallyconfigure a UE with a maximum number of front-loaded DM-RS symbols forPDSCH 514. For example, a DM-RS configuration may support one or moreDM-RS ports. For example, for single user-MIMO, a DM-RS configurationmay support at least 8 orthogonal downlink DM-RS ports. For example, formultiuser-MIMO, a DM-RS configuration may support 12 orthogonal downlinkDM-RS ports. A radio network may support, e.g., at least for CP-OFDM, acommon DM-RS structure for DL and UL, wherein a DM-RS location, DM-RSpattern, and/or scrambling sequence may be same or different.

In an example, whether downlink PT-RS 524 is present or not may dependon a RRC configuration. For example, a presence of downlink PT-RS 524may be UE-specifically configured. For example, a presence and/or apattern of downlink PT-RS 524 in a scheduled resource may beUE-specifically configured by a combination of RRC signaling and/orassociation with one or more parameters employed for other purposes(e.g., MCS) which may be indicated by DCI. When configured, a dynamicpresence of downlink PT-RS 524 may be associated with one or more DCIparameters comprising at least MCS. A radio network may supportplurality of PT-RS densities defined in time/frequency domain. Whenpresent, a frequency domain density may be associated with at least oneconfiguration of a scheduled bandwidth. A UE may assume a same precodingfor a DMRS port and a PT-RS port. A number of PT-RS ports may be fewerthan a number of DM-RS ports in a scheduled resource. For example,downlink PT-RS 524 may be confined in the scheduled time/frequencyduration for a UE.

FIG. 6 is a diagram depicting an example transmission time and receptiontime for a carrier as per an aspect of an embodiment of the presentdisclosure. A multicarrier OFDM communication system may include one ormore carriers, for example, ranging from 1 to 32 carriers, in case ofcarrier aggregation, or ranging from 1 to 64 carriers, in case of dualconnectivity. Different radio frame structures may be supported (e.g.,for FDD and for TDD duplex mechanisms). FIG. 6 shows an example frametiming. Downlink and uplink transmissions may be organized into radioframes 601. In this example, radio frame duration is 10 ms. In thisexample, a 10 ms radio frame 601 may be divided into ten equally sizedsubframes 602 with 1 ms duration. Subframe(s) may comprise one or moreslots (e.g. slots 603 and 605) depending on subcarrier spacing and/or CPlength. For example, a subframe with 15 kHz, 30 kHz, 60 kHz, 120 kHz,240 kHz and 480 kHz subcarrier spacing may comprise one, two, four,eight, sixteen and thirty-two slots, respectively. In FIG. 6 , asubframe may be divided into two equally sized slots 603 with 0.5 msduration. For example, 10 subframes may be available for downlinktransmission and 10 subframes may be available for uplink transmissionsin a 10 ms interval. Uplink and downlink transmissions may be separatedin the frequency domain. Slot(s) may include a plurality of OFDM symbols604. The number of OFDM symbols 604 in a slot 605 may depend on thecyclic prefix length. For example, a slot may be 14 OFDM symbols for thesame subcarrier spacing of up to 480 kHz with normal CP. A slot may be12 OFDM symbols for the same subcarrier spacing of 60 kHz with extendedCP. A slot may contain downlink, uplink, or a downlink part and anuplink part and/or alike.

FIG. 7A is a diagram depicting example sets of OFDM subcarriers as peran aspect of an embodiment of the present disclosure. In the example, agNB may communicate with a wireless device with a carrier with anexample channel bandwidth 700. Arrow(s) in the diagram may depict asubcarrier in a multicarrier OFDM system. The OFDM system may usetechnology such as OFDM technology, SC-FDMA technology, and/or the like.In an example, an arrow 701 shows a subcarrier transmitting informationsymbols. In an example, a subcarrier spacing 702, between two contiguoussubcarriers in a carrier, may be any one of 15 KHz, 30 KHz, 60 KHz, 120KHz, 240 KHz etc. In an example, different subcarrier spacing maycorrespond to different transmission numerologies. In an example, atransmission numerology may comprise at least: a numerology index; avalue of subcarrier spacing; a type of cyclic prefix (CP). In anexample, a gNB may transmit to/receive from a UE on a number ofsubcarriers 703 in a carrier. In an example, a bandwidth occupied by anumber of subcarriers 703 (transmission bandwidth) may be smaller thanthe channel bandwidth 700 of a carrier, due to guard band 704 and 705.In an example, a guard band 704 and 705 may be used to reduceinterference to and from one or more neighbor carriers. A number ofsubcarriers (transmission bandwidth) in a carrier may depend on thechannel bandwidth of the carrier and the subcarrier spacing. Forexample, a transmission bandwidth, for a carrier with 20 MHz channelbandwidth and 15 KHz subcarrier spacing, may be in number of 1024subcarriers.

In an example, a gNB and a wireless device may communicate with multipleCCs when configured with CA. In an example, different component carriersmay have different bandwidth and/or subcarrier spacing, if CA issupported. In an example, a gNB may transmit a first type of service toa UE on a first component carrier. The gNB may transmit a second type ofservice to the UE on a second component carrier. Different type ofservices may have different service requirement (e.g., data rate,latency, reliability), which may be suitable for transmission viadifferent component carrier having different subcarrier spacing and/orbandwidth. FIG. 7B shows an example embodiment. A first componentcarrier may comprise a first number of subcarriers 706 with a firstsubcarrier spacing 709. A second component carrier may comprise a secondnumber of subcarriers 707 with a second subcarrier spacing 710. A thirdcomponent carrier may comprise a third number of subcarriers 708 with athird subcarrier spacing 711. Carriers in a multicarrier OFDMcommunication system may be contiguous carriers, non-contiguouscarriers, or a combination of both contiguous and non-contiguouscarriers.

FIG. 8 is a diagram depicting OFDM radio resources as per an aspect ofan embodiment of the present disclosure. In an example, a carrier mayhave a transmission bandwidth 801. In an example, a resource grid may bein a structure of frequency domain 802 and time domain 803. In anexample, a resource grid may comprise a first number of OFDM symbols ina subframe and a second number of resource blocks, starting from acommon resource block indicated by higher-layer signaling (e.g. RRCsignaling), for a transmission numerology and a carrier. In an example,in a resource grid, a resource unit identified by a subcarrier index anda symbol index may be a resource element 805. In an example, a subframemay comprise a first number of OFDM symbols 807 depending on anumerology associated with a carrier. For example, when a subcarrierspacing of a numerology of a carrier is 15 KHz, a subframe may have 14OFDM symbols for a carrier. When a subcarrier spacing of a numerology is30 KHz, a subframe may have 28 OFDM symbols. When a subcarrier spacingof a numerology is 60 Khz, a subframe may have 56 OFDM symbols, etc. Inan example, a second number of resource blocks comprised in a resourcegrid of a carrier may depend on a bandwidth and a numerology of thecarrier.

As shown in FIG. 8 , a resource block 806 may comprise 12 subcarriers.In an example, multiple resource blocks may be grouped into a ResourceBlock Group (RBG) 804. In an example, a size of a RBG may depend on atleast one of: a RRC message indicating a RBG size configuration; a sizeof a carrier bandwidth; or a size of a bandwidth part of a carrier. Inan example, a carrier may comprise multiple bandwidth parts. A firstbandwidth part of a carrier may have different frequency location and/orbandwidth from a second bandwidth part of the carrier.

In an example, a gNB may transmit a downlink control informationcomprising a downlink or uplink resource block assignment to a wirelessdevice. A base station may transmit to or receive from, a wirelessdevice, data packets (e.g. transport blocks) scheduled and transmittedvia one or more resource blocks and one or more slots according toparameters in a downlink control information and/or RRC message(s). Inan example, a starting symbol relative to a first slot of the one ormore slots may be indicated to the wireless device. In an example, a gNBmay transmit to or receive from, a wireless device, data packetsscheduled on one or more RBGs and one or more slots.

In an example, a gNB may transmit a downlink control informationcomprising a downlink assignment to a wireless device via one or morePDCCHs. The downlink assignment may comprise parameters indicating atleast modulation and coding format; resource allocation; and/or HARQinformation related to DL-SCH. In an example, a resource allocation maycomprise parameters of resource block allocation; and/or slotallocation. In an example, a gNB may dynamically allocate resources to awireless device via a Cell-Radio Network Temporary Identifier (C-RNTI)on one or more PDCCHs. The wireless device may monitor the one or morePDCCHs in order to find possible allocation when its downlink receptionis enabled. The wireless device may receive one or more downlink datapackage on one or more PDSCH scheduled by the one or more PDCCHs, whensuccessfully detecting the one or more PDCCHs.

In an example, a gNB may allocate Configured Scheduling (CS) resourcesfor down link transmission to a wireless device. The gNB may transmitone or more RRC messages indicating a periodicity of the CS grant. ThegNB may transmit a DCI via a PDCCH addressed to a ConfiguredScheduling-RNTI (CS-RNTI) activating the CS resources. The DCI maycomprise parameters indicating that the downlink grant is a CS grant.The CS grant may be implicitly reused according to the periodicitydefined by the one or more RRC messages, until deactivated.

In an example, a gNB may transmit a downlink control informationcomprising an uplink grant to a wireless device via one or more PDCCHs.The uplink grant may comprise parameters indicating at least modulationand coding format; resource allocation; and/or HARQ information relatedto UL-SCH. In an example, a resource allocation may comprise parametersof resource block allocation; and/or slot allocation. In an example, agNB may dynamically allocate resources to a wireless device via a C-RNTIon one or more PDCCHs. The wireless device may monitor the one or morePDCCHs in order to find possible resource allocation. The wirelessdevice may transmit one or more uplink data package via one or morePUSCH scheduled by the one or more PDCCHs, when successfully detectingthe one or more PDCCHs.

In an example, a gNB may allocate CS resources for uplink datatransmission to a wireless device. The gNB may transmit one or more RRCmessages indicating a periodicity of the CS grant. The gNB may transmita DCI via a PDCCH addressed to a CS-RNTI activating the CS resources.The DCI may comprise parameters indicating that the uplink grant is a CSgrant. The CS grant may be implicitly reused according to theperiodicity defined by the one or more RRC message, until deactivated.

In an example, a base station may transmit DCI/control signaling viaPDCCH. The DCI may take a format in a plurality of formats. A DCI maycomprise downlink and/or uplink scheduling information (e.g., resourceallocation information, HARQ related parameters, MCS), request for CSI(e.g., aperiodic CQI reports), request for SRS, uplink power controlcommands for one or more cells, one or more timing information (e.g., TBtransmission/reception timing, HARQ feedback timing, etc.), etc. In anexample, a DCI may indicate an uplink grant comprising transmissionparameters for one or more transport blocks. In an example, a DCI mayindicate downlink assignment indicating parameters for receiving one ormore transport blocks. In an example, a DCI may be used by base stationto initiate a contention-free random access at the wireless device. Inan example, the base station may transmit a DCI comprising slot formatindicator (SFI) notifying a slot format. In an example, the base stationmay transmit a DCI comprising pre-emption indication notifying thePRB(s) and/or OFDM symbol(s) where a UE may assume no transmission isintended for the UE. In an example, the base station may transmit a DCIfor group power control of PUCCH or PUSCH or SRS. In an example, a DCImay correspond to an RNTI. In an example, the wireless device may obtainan RNTI in response to completing the initial access (e.g., C-RNTI). Inan example, the base station may configure an RNTI for the wireless(e.g., CS-RNTI, TPC-CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI,TPC-SRS-RNTI). In an example, the wireless device may compute an RNTI(e.g., the wireless device may compute RA-RNTI based on resources usedfor transmission of a preamble). In an example, an RNTI may have apre-configured value (e.g., P-RNTI or SI-RNTI). In an example, awireless device may monitor a group common search space which may beused by base station for transmitting DCIs that are intended for a groupof UEs. In an example, a group common DCI may correspond to an RNTIwhich is commonly configured for a group of UEs. In an example, awireless device may monitor a UE-specific search space. In an example, aUE specific DCI may correspond to an RNTI configured for the wirelessdevice.

A NR system may support a single beam operation and/or a multi-beamoperation. In a multi-beam operation, a base station may perform adownlink beam sweeping to provide coverage for common control channelsand/or downlink SS blocks, which may comprise at least a PSS, a SSS,and/or PBCH. A wireless device may measure quality of a beam pair linkusing one or more RSs. One or more SS blocks, or one or more CSI-RSresources, associated with a CSI-RS resource index (CRI), or one or moreDM-RSs of PBCH, may be used as RS for measuring quality of a beam pairlink. Quality of a beam pair link may be defined as a reference signalreceived power (RSRP) value, or a reference signal received quality(RSRQ) value, and/or a CSI value measured on RS resources. The basestation may indicate whether an RS resource, used for measuring a beampair link quality, is quasi-co-located (QCLed) with DM-RSs of a controlchannel. A RS resource and DM-RSs of a control channel may be calledQCLed when a channel characteristics from a transmission on an RS to awireless device, and that from a transmission on a control channel to awireless device, are similar or same under a configured criterion. In amulti-beam operation, a wireless device may perform an uplink beamsweeping to access a cell.

In an example, a wireless device may be configured to monitor PDCCH onone or more beam pair links simultaneously depending on a capability ofa wireless device. This may increase robustness against beam pair linkblocking. A base station may transmit one or more messages to configurea wireless device to monitor PDCCH on one or more beam pair links indifferent PDCCH OFDM symbols. For example, a base station may transmithigher layer signaling (e.g. RRC signaling) or MAC CE comprisingparameters related to the Rx beam setting of a wireless device formonitoring PDCCH on one or more beam pair links. A base station maytransmit indication of spatial QCL assumption between an DL RS antennaport(s) (for example, cell-specific CSI-RS, or wireless device-specificCSI-RS, or SS block, or PBCH with or without DM-RSs of PBCH), and DL RSantenna port(s) for demodulation of DL control channel. Signaling forbeam indication for a PDCCH may be MAC CE signaling, or RRC signaling,or DCI signaling, or specification-transparent and/or implicit method,and combination of these signaling methods.

For reception of unicast DL data channel, a base station may indicatespatial QCL parameters between DL RS antenna port(s) and DM-RS antennaport(s) of DL data channel. The base station may transmit DCI (e.g.downlink grants) comprising information indicating the RS antennaport(s). The information may indicate RS antenna port(s) which may beQCL-ed with the DM-RS antenna port(s). Different set of DM-RS antennaport(s) for a DL data channel may be indicated as QCL with different setof the RS antenna port(s).

FIG. 9A is an example of beam sweeping in a DL channel. In anRRC_INACTIVE state or RRC_IDLE state, a wireless device may assume thatSS blocks form an SS burst 940, and an SS burst set 950. The SS burstset 950 may have a given periodicity. For example, in a multi-beamoperation, a base station 120 may transmit SS blocks in multiple beams,together forming a SS burst 940. One or more SS blocks may betransmitted on one beam. If multiple SS bursts 940 are transmitted withmultiple beams, SS bursts together may form SS burst set 950.

A wireless device may further use CSI-RS in the multi-beam operation forestimating a beam quality of a links between a wireless device and abase station. A beam may be associated with a CSI-RS. For example, awireless device may, based on a RSRP measurement on CSI-RS, report abeam index, as indicated in a CRI for downlink beam selection, andassociated with a RSRP value of a beam. A CSI-RS may be transmitted on aCSI-RS resource including at least one of one or more antenna ports, oneor more time or frequency radio resources. A CSI-RS resource may beconfigured in a cell-specific way by common RRC signaling, or in awireless device-specific way by dedicated RRC signaling, and/or L1/L2signaling. Multiple wireless devices covered by a cell may measure acell-specific CSI-RS resource. A dedicated subset of wireless devicescovered by a cell may measure a wireless device-specific CSI-RSresource.

A CSI-RS resource may be transmitted periodically, or using aperiodictransmission, or using a multi-shot or semi-persistent transmission. Forexample, in a periodic transmission in FIG. 9A, a base station 120 maytransmit configured CSI-RS resources 940 periodically using a configuredperiodicity in a time domain. In an aperiodic transmission, a configuredCSI-RS resource may be transmitted in a dedicated time slot. In amulti-shot or semi-persistent transmission, a configured CSI-RS resourcemay be transmitted within a configured period. Beams used for CSI-RStransmission may have different beam width than beams used for SS-blockstransmission.

FIG. 9B is an example of a beam management procedure in an example newradio network. A base station 120 and/or a wireless device 110 mayperform a downlink L1/L2 beam management procedure. One or more of thefollowing downlink L1/L2 beam management procedures may be performedwithin one or more wireless devices 110 and one or more base stations120. In an example, a P-1 procedure 910 may be used to enable thewireless device 110 to measure one or more Transmission (Tx) beamsassociated with the base station 120 to support a selection of a firstset of Tx beams associated with the base station 120 and a first set ofRx beam(s) associated with a wireless device 110. For beamforming at abase station 120, a base station 120 may sweep a set of different TXbeams. For beamforming at a wireless device 110, a wireless device 110may sweep a set of different Rx beams. In an example, a P-2 procedure920 may be used to enable a wireless device 110 to measure one or moreTx beams associated with a base station 120 to possibly change a firstset of Tx beams associated with a base station 120. A P-2 procedure 920may be performed on a possibly smaller set of beams for beam refinementthan in the P-1 procedure 910. A P-2 procedure 920 may be a special caseof a P-1 procedure 910. In an example, a P-3 procedure 930 may be usedto enable a wireless device 110 to measure at least one Tx beamassociated with a base station 120 to change a first set of Rx beamsassociated with a wireless device 110.

A wireless device 110 may transmit one or more beam management reportsto a base station 120. In one or more beam management reports, awireless device 110 may indicate some beam pair quality parameters,comprising at least, one or more beam identifications; RSRP; PrecodingMatrix Indicator (PMI)/Channel Quality Indicator (CQI)/Rank Indicator(RI) of a subset of configured beams. Based on one or more beammanagement reports, a base station 120 may transmit to a wireless device110 a signal indicating that one or more beam pair links are one or moreserving beams. A base station 120 may transmit PDCCH and PDSCH for awireless device 110 using one or more serving beams.

In an example embodiment, new radio network may support a BandwidthAdaptation (BA). In an example, receive and/or transmit bandwidthsconfigured by an UE employing a BA may not be large. For example, areceive and/or transmit bandwidths may not be as large as a bandwidth ofa cell. Receive and/or transmit bandwidths may be adjustable. Forexample, a UE may change receive and/or transmit bandwidths, e.g., toshrink during period of low activity to save power. For example, a UEmay change a location of receive and/or transmit bandwidths in afrequency domain, e.g. to increase scheduling flexibility. For example,a UE may change a subcarrier spacing, e.g. to allow different services.

In an example embodiment, a subset of a total cell bandwidth of a cellmay be referred to as a Bandwidth Part (BWP). A base station mayconfigure a UE with one or more BWPs to achieve a BA. For example, abase station may indicate, to a UE, which of the one or more(configured) BWPs is an active BWP.

FIG. 10 is an example diagram of 3 BWPs configured: BWP1 (1010 and 1050)with a width of 40 MHz and subcarrier spacing of 15 kHz; BWP2 (1020 and1040) with a width of 10 MHz and subcarrier spacing of 15 kHz; BWP3 1030with a width of 20 MHz and subcarrier spacing of 60 kHz.

In an example, a UE, configured for operation in one or more BWPs of acell, may be configured by one or more higher layers (e.g. RRC layer)for a cell a set of one or more BWPs (e.g., at most four BWPs) forreceptions by the UE (DL BWP set) in a DL bandwidth by at least oneparameter DL-BWP and a set of one or more BWPs (e.g., at most four BWPs)for transmissions by a UE (UL BWP set) in an UL bandwidth by at leastone parameter UL-BWP for a cell.

To enable BA on the PCell, a base station may configure a UE with one ormore UL and DL BWP pairs. To enable BA on SCells (e.g., in case of CA),a base station may configure a UE at least with one or more DL BWPs(e.g., there may be none in an UL).

In an example, an initial active DL BWP may be defined by at least oneof a location and number of contiguous PRBs, a subcarrier spacing, or acyclic prefix, for a control resource set for at least one common searchspace. For operation on the PCell, one or more higher layer parametersmay indicate at least one initial UL BWP for a random access procedure.If a UE is configured with a secondary carrier on a primary cell, the UEmay be configured with an initial BWP for random access procedure on asecondary carrier.

In an example, for unpaired spectrum operation, a UE may expect that acenter frequency for a DL BWP may be same as a center frequency for a ULBWP.

For example, for a DL BWP or an UL BWP in a set of one or more DL BWPsor one or more UL BWPs, respectively, a base statin maysemi-statistically configure a UE for a cell with one or more parametersindicating at least one of following: a subcarrier spacing; a cyclicprefix; a number of contiguous PRBs; an index in the set of one or moreDL BWPs and/or one or more UL BWPs; a link between a DL BWP and an ULBWP from a set of configured DL BWPs and UL BWPs; a DCI detection to aPDSCH reception timing; a PDSCH reception to a HARQ-ACK transmissiontiming value; a DCI detection to a PUSCH transmission timing value; anoffset of a first PRB of a DL bandwidth or an UL bandwidth,respectively, relative to a first PRB of a bandwidth.

In an example, for a DL BWP in a set of one or more DL BWPs on a PCell,a base station may configure a UE with one or more control resource setsfor at least one type of common search space and/or one UE-specificsearch space. For example, a base station may not configure a UE withouta common search space on a PCell, or on a PSCell, in an active DL BWP.

For an UL BWP in a set of one or more UL BWPs, a base station mayconfigure a UE with one or more resource sets for one or more PUCCHtransmissions.

In an example, if a DCI comprises a BWP indicator field, a BWP indicatorfield value may indicate an active DL BWP, from a configured DL BWP set,for one or more DL receptions. If a DCI comprises a BWP indicator field,a BWP indicator field value may indicate an active UL BWP, from aconfigured UL BWP set, for one or more UL transmissions.

In an example, for a PCell, a base station may semi-statisticallyconfigure a UE with a default DL BWP among configured DL BWPs. If a UEis not provided a default DL BWP, a default BWP may be an initial activeDL BWP.

In an example, a base station may configure a UE with a timer value fora PCell. For example, a UE may start a timer, referred to as BWPinactivity timer, when a UE detects a DCI indicating an active DL BWP,other than a default DL BWP, for a paired spectrum operation or when aUE detects a DCI indicating an active DL BWP or UL BWP, other than adefault DL BWP or UL BWP, for an unpaired spectrum operation. The UE mayincrement the timer by an interval of a first value (e.g., the firstvalue may be 1 millisecond or 0.5 milliseconds) if the UE does notdetect a DCI during the interval for a paired spectrum operation or foran unpaired spectrum operation. In an example, the timer may expire whenthe timer is equal to the timer value. A UE may switch to the default DLBWP from an active DL BWP when the timer expires.

In an example, a base station may semi-statistically configure a UE withone or more BWPs. A UE may switch an active BWP from a first BWP to asecond BWP in response to receiving a DCI indicating the second BWP asan active BWP and/or in response to an expiry of BWP inactivity timer(for example, the second BWP may be a default BWP). For example, FIG. 10is an example diagram of 3 BWPs configured, BWP1 (1010 and 1050), BWP2(1020 and 1040), and BWP3 (1030). BWP2 (1020 and 1040) may be a defaultBWP. BWP1 (1010) may be an initial active BWP. In an example, a UE mayswitch an active BWP from BWP1 1010 to BWP2 1020 in response to anexpiry of BWP inactivity timer. For example, a UE may switch an activeBWP from BWP2 1020 to BWP3 1030 in response to receiving a DCIindicating BWP3 1030 as an active BWP. Switching an active BWP from BWP31030 to BWP2 1040 and/or from BWP2 1040 to BWP1 1050 may be in responseto receiving a DCI indicating an active BWP and/or in response to anexpiry of BWP inactivity timer.

In an example, if a UE is configured for a secondary cell with a defaultDL BWP among configured DL BWPs and a timer value, UE procedures on asecondary cell may be same as on a primary cell using the timer valuefor the secondary cell and the default DL BWP for the secondary cell.

In an example, if a base station configures a UE with a first active DLBWP and a first active UL BWP on a secondary cell or carrier, a UE mayemploy an indicated DL BWP and an indicated UL BWP on a secondary cellas a respective first active DL BWP and first active UL BWP on asecondary cell or carrier.

FIG. 11A and FIG. 11B show packet flows employing a multi connectivity(e.g. dual connectivity, multi connectivity, tight interworking, and/orthe like). FIG. 11A is an example diagram of a protocol structure of awireless device 110 (e.g. UE) with CA and/or multi connectivity as peran aspect of an embodiment. FIG. 11B is an example diagram of a protocolstructure of multiple base stations with CA and/or multi connectivity asper an aspect of an embodiment. The multiple base stations may comprisea master node, MN 1130 (e.g. a master node, a master base station, amaster gNB, a master eNB, and/or the like) and a secondary node, SN 1150(e.g. a secondary node, a secondary base station, a secondary gNB, asecondary eNB, and/or the like). A master node 1130 and a secondary node1150 may co-work to communicate with a wireless device 110.

When multi connectivity is configured for a wireless device 110, thewireless device 110, which may support multiple reception/transmissionfunctions in an RRC connected state, may be configured to utilize radioresources provided by multiple schedulers of a multiple base stations.Multiple base stations may be inter-connected via a non-ideal or idealbackhaul (e.g. Xn interface, X2 interface, and/or the like). A basestation involved in multi connectivity for a certain wireless device mayperform at least one of two different roles: a base station may eitheract as a master base station or as a secondary base station. In multiconnectivity, a wireless device may be connected to one master basestation and one or more secondary base stations. In an example, a masterbase station (e.g. the MN 1130) may provide a master cell group (MCG)comprising a primary cell and/or one or more secondary cells for awireless device (e.g. the wireless device 110). A secondary base station(e.g. the SN 1150) may provide a secondary cell group (SCG) comprising aprimary secondary cell (PSCell) and/or one or more secondary cells for awireless device (e.g. the wireless device 110).

In multi connectivity, a radio protocol architecture that a beareremploys may depend on how a bearer is setup. In an example, threedifferent type of bearer setup options may be supported: an MCG bearer,an SCG bearer, and/or a split bearer. A wireless device mayreceive/transmit packets of an MCG bearer via one or more cells of theMCG, and/or may receive/transmits packets of an SCG bearer via one ormore cells of an SCG. Multi-connectivity may also be described as havingat least one bearer configured to use radio resources provided by thesecondary base station. Multi-connectivity may or may not beconfigured/implemented in some of the example embodiments.

In an example, a wireless device (e.g. Wireless Device 110) may transmitand/or receive: packets of an MCG bearer via an SDAP layer (e.g. SDAP1110), a PDCP layer (e.g. NR PDCP 1111), an RLC layer (e.g. MN RLC1114), and a MAC layer (e.g. MN MAC 1118); packets of a split bearer viaan SDAP layer (e.g. SDAP 1110), a PDCP layer (e.g. NR PDCP 1112), one ofa master or secondary RLC layer (e.g. MN RLC 1115, SN RLC 1116), and oneof a master or secondary MAC layer (e.g. MN MAC 1118, SN MAC 1119);and/or packets of an SCG bearer via an SDAP layer (e.g. SDAP 1110), aPDCP layer (e.g. NR PDCP 1113), an RLC layer (e.g. SN RLC 1117), and aMAC layer (e.g. MN MAC 1119).

In an example, a master base station (e.g. MN 1130) and/or a secondarybase station (e.g. SN 1150) may transmit/receive: packets of an MCGbearer via a master or secondary node SDAP layer (e.g. SDAP 1120, SDAP1140), a master or secondary node PDCP layer (e.g. NR PDCP 1121, NR PDCP1142), a master node RLC layer (e.g. MN RLC 1124, MN RLC 1125), and amaster node MAC layer (e.g. MN MAC 1128); packets of an SCG bearer via amaster or secondary node SDAP layer (e.g. SDAP 1120, SDAP 1140), amaster or secondary node PDCP layer (e.g. NR PDCP 1122, NR PDCP 1143), asecondary node RLC layer (e.g. SN RLC 1146, SN RLC 1147), and asecondary node MAC layer (e.g. SN MAC 1148); packets of a split bearervia a master or secondary node SDAP layer (e.g. SDAP 1120, SDAP 1140), amaster or secondary node PDCP layer (e.g. NR PDCP 1123, NR PDCP 1141), amaster or secondary node RLC layer (e.g. MN RLC 1126, SN RLC 1144, SNRLC 1145, MN RLC 1127), and a master or secondary node MAC layer (e.g.MN MAC 1128, SN MAC 1148).

In multi connectivity, a wireless device may configure multiple MACentities: one MAC entity (e.g. MN MAC 1118) for a master base station,and other MAC entities (e.g. SN MAC 1119) for a secondary base station.In multi-connectivity, a configured set of serving cells for a wirelessdevice may comprise two subsets: an MCG comprising serving cells of amaster base station, and SCGs comprising serving cells of a secondarybase station. For an SCG, one or more of following configurations may beapplied: at least one cell of an SCG has a configured UL CC and at leastone cell of a SCG, named as primary secondary cell (PSCell, PCell ofSCG, or sometimes called PCell), is configured with PUCCH resources;when an SCG is configured, there may be at least one SCG bearer or oneSplit bearer; upon detection of a physical layer problem or a randomaccess problem on a PSCell, or a number of NR RLC retransmissions hasbeen reached associated with the SCG, or upon detection of an accessproblem on a PSCell during a SCG addition or a SCG change: an RRCconnection re-establishment procedure may not be triggered, ULtransmissions towards cells of an SCG may be stopped, a master basestation may be informed by a wireless device of a SCG failure type, forsplit bearer, a DL data transfer over a master base station may bemaintained; an NR RLC acknowledged mode (AM) bearer may be configuredfor a split bearer; PCell and/or PSCell may not be de-activated; PSCellmay be changed with a SCG change procedure (e.g. with security keychange and a RACH procedure); and/or a bearer type change between asplit bearer and a SCG bearer or simultaneous configuration of a SCG anda split bearer may or may not supported.

With respect to interaction between a master base station and asecondary base stations for multi-connectivity, one or more of thefollowing may be applied: a master base station and/or a secondary basestation may maintain RRM measurement configurations of a wirelessdevice; a master base station may (e.g. based on received measurementreports, traffic conditions, and/or bearer types) may decide to requesta secondary base station to provide additional resources (e.g. servingcells) for a wireless device; upon receiving a request from a masterbase station, a secondary base station may create/modify a containerthat may result in configuration of additional serving cells for awireless device (or decide that the secondary base station has noresource available to do so); for a UE capability coordination, a masterbase station may provide (a part of) an AS configuration and UEcapabilities to a secondary base station; a master base station and asecondary base station may exchange information about a UE configurationby employing of RRC containers (inter-node messages) carried via Xnmessages; a secondary base station may initiate a reconfiguration of thesecondary base station existing serving cells (e.g. PUCCH towards thesecondary base station); a secondary base station may decide which cellis a PSCell within a SCG; a master base station may or may not changecontent of RRC configurations provided by a secondary base station; incase of a SCG addition and/or a SCG SCell addition, a master basestation may provide recent (or the latest) measurement results for SCGcell(s); a master base station and secondary base stations may receiveinformation of SFN and/or subframe offset of each other from OAM and/orvia an Xn interface, (e.g. for a purpose of DRX alignment and/oridentification of a measurement gap). In an example, when adding a newSCG SCell, dedicated RRC signaling may be used for sending requiredsystem information of a cell as for CA, except for a SFN acquired from aMIB of a PSCell of a SCG.

FIG. 12 is an example diagram of a random access procedure. One or moreevents may trigger a random access procedure. For example, one or moreevents may be at least one of following: initial access from RRC_IDLE,RRC connection re-establishment procedure, handover, DL or UL dataarrival during RRC_CONNECTED when UL synchronization status isnon-synchronised, transition from RRC_Inactive, and/or request for othersystem information. For example, a PDCCH order, a MAC entity, and/or abeam failure indication may initiate a random access procedure.

In an example embodiment, a random access procedure may be at least oneof a contention based random access procedure and a contention freerandom access procedure. For example, a contention based random accessprocedure may comprise, one or more Msg 1 1220 transmissions, one ormore Msg2 1230 transmissions, one or more Msg3 1240 transmissions, andcontention resolution 1250. For example, a contention free random accessprocedure may comprise one or more Msg 1 1220 transmissions and one ormore Msg2 1230 transmissions.

In an example, a base station may transmit (e.g., unicast, multicast, orbroadcast), to a UE, a RACH configuration 1210 via one or more beams.The RACH configuration 1210 may comprise one or more parametersindicating at least one of following: available set of PRACH resourcesfor a transmission of a random access preamble, initial preamble power(e.g., random access preamble initial received target power), an RSRPthreshold for a selection of a SS block and corresponding PRACHresource, a power-ramping factor (e.g., random access preamble powerramping step), random access preamble index, a maximum number ofpreamble transmission, preamble group A and group B, a threshold (e.g.,message size) to determine the groups of random access preambles, a setof one or more random access preambles for system information requestand corresponding PRACH resource(s), if any, a set of one or more randomaccess preambles for beam failure recovery request and correspondingPRACH resource(s), if any, a time window to monitor RA response(s), atime window to monitor response(s) on beam failure recovery request,and/or a contention resolution timer.

In an example, the Msg1 1220 may be one or more transmissions of arandom access preamble. For a contention based random access procedure,a UE may select a SS block with a RSRP above the RSRP threshold. Ifrandom access preambles group B exists, a UE may select one or morerandom access preambles from a group A or a group B depending on apotential Msg3 1240 size. If a random access preambles group B does notexist, a UE may select the one or more random access preambles from agroup A. A UE may select a random access preamble index randomly (e.g.with equal probability or a normal distribution) from one or more randomaccess preambles associated with a selected group. If a base stationsemi-statistically configures a UE with an association between randomaccess preambles and SS blocks, the UE may select a random accesspreamble index randomly with equal probability from one or more randomaccess preambles associated with a selected SS block and a selectedgroup.

For example, a UE may initiate a contention free random access procedurebased on a beam failure indication from a lower layer. For example, abase station may semi-statistically configure a UE with one or morecontention free PRACH resources for beam failure recovery requestassociated with at least one of SS blocks and/or CSI-RSs. If at leastone of SS blocks with a RSRP above a first RSRP threshold amongstassociated SS blocks or at least one of CSI-RSs with a RSRP above asecond RSRP threshold amongst associated CSI-RSs is available, a UE mayselect a random access preamble index corresponding to a selected SSblock or CSI-RS from a set of one or more random access preambles forbeam failure recovery request.

For example, a UE may receive, from a base station, a random accesspreamble index via PDCCH or RRC for a contention free random accessprocedure. If a base station does not configure a UE with at least onecontention free PRACH resource associated with SS blocks or CSI-RS, theUE may select a random access preamble index. If a base stationconfigures a UE with one or more contention free PRACH resourcesassociated with SS blocks and at least one SS block with a RSRP above afirst RSRP threshold amongst associated SS blocks is available, the UEmay select the at least one SS block and select a random access preamblecorresponding to the at least one SS block. If a base station configuresa UE with one or more contention free PRACH resources associated withCSI-RSs and at least one CSI-RS with a RSRP above a second RSPRthreshold amongst the associated CSI-RSs is available, the UE may selectthe at least one CSI-RS and select a random access preamblecorresponding to the at least one CSI-RS.

A UE may perform one or more Msg1 1220 transmissions by transmitting theselected random access preamble. For example, if a UE selects an SSblock and is configured with an association between one or more PRACHoccasions and one or more SS blocks, the UE may determine an PRACHoccasion from one or more PRACH occasions corresponding to a selected SSblock. For example, if a UE selects a CSI-RS and is configured with anassociation between one or more PRACH occasions and one or more CSI-RSs,the UE may determine a PRACH occasion from one or more PRACH occasionscorresponding to a selected CSI-RS. A UE may transmit, to a basestation, a selected random access preamble via a selected PRACHoccasions. A UE may determine a transmit power for a transmission of aselected random access preamble at least based on an initial preamblepower and a power-ramping factor. A UE may determine a RA-RNTIassociated with a selected PRACH occasions in which a selected randomaccess preamble is transmitted. For example, a UE may not determine aRA-RNTI for a beam failure recovery request. A UE may determine anRA-RNTI at least based on an index of a first OFDM symbol and an indexof a first slot of a selected PRACH occasions, and/or an uplink carrierindex for a transmission of Msg1 1220.

In an example, a UE may receive, from a base station, a random accessresponse, Msg 2 1230. A UE may start a time window (e.g.,ra-ResponseWindow) to monitor a random access response. For beam failurerecovery request, a base station may configure a UE with a differenttime window (e.g., bfr-ResponseWindow) to monitor response on beamfailure recovery request. For example, a UE may start a time window(e.g., ra-ResponseWindow or bfr-ResponseWindow) at a start of a firstPDCCH occasion after a fixed duration of one or more symbols from an endof a preamble transmission. If a UE transmits multiple preambles, the UEmay start a time window at a start of a first PDCCH occasion after afixed duration of one or more symbols from an end of a first preambletransmission. A UE may monitor a PDCCH of a cell for at least one randomaccess response identified by a RA-RNTI or for at least one response tobeam failure recovery request identified by a C-RNTI while a timer for atime window is running.

In an example, a UE may consider a reception of random access responsesuccessful if at least one random access response comprises a randomaccess preamble identifier corresponding to a random access preambletransmitted by the UE. A UE may consider the contention free randomaccess procedure successfully completed if a reception of random accessresponse is successful. If a contention free random access procedure istriggered for a beam failure recovery request, a UE may consider acontention free random access procedure successfully complete if a PDCCHtransmission is addressed to a C-RNTI. In an example, if at least onerandom access response comprises only a random access preambleidentifier, a UE may consider the random access procedure successfullycompleted and may indicate a reception of an acknowledgement for asystem information request to upper layers. If a UE has signaledmultiple preamble transmissions, the UE may stop transmitting remainingpreambles (if any) in response to a successful reception of acorresponding random access response.

In an example, a UE may perform one or more Msg 3 1240 transmissions inresponse to a successful reception of random access response (e.g., fora contention based random access procedure). A UE may adjust an uplinktransmission timing based on a timing advanced command indicated by arandom access response and may transmit one or more transport blocksbased on an uplink grant indicated by a random access response.Subcarrier spacing for PUSCH transmission for Msg3 1240 may be providedby at least one higher layer (e.g. RRC) parameter. A UE may transmit arandom access preamble via PRACH and Msg3 1240 via PUSCH on a same cell.A base station may indicate an UL BWP for a PUSCH transmission of Msg31240 via system information block. A UE may employ HARQ for aretransmission of Msg 3 1240.

In an example, multiple UEs may perform Msg 1 1220 by transmitting asame preamble to a base station and receive, from the base station, asame random access response comprising an identity (e.g., TC-RNTI).Contention resolution 1250 may ensure that a UE does not incorrectly usean identity of another UE. For example, contention resolution 1250 maybe based on C-RNTI on PDCCH or a UE contention resolution identity onDL-SCH. For example, if a base station assigns a C-RNTI to a UE, the UEmay perform contention resolution 1250 based on a reception of a PDCCHtransmission that is addressed to the C-RNTI. In response to detectionof a C-RNTI on a PDCCH, a UE may consider contention resolution 1250successful and may consider a random access procedure successfullycompleted. If a UE has no valid C-RNTI, a contention resolution may beaddressed by employing a TC-RNTI. For example, if a MAC PDU issuccessfully decoded and a MAC PDU comprises a UE contention resolutionidentity MAC CE that matches the CCCH SDU transmitted in Msg3 1250, a UEmay consider the contention resolution 1250 successful and may considerthe random access procedure successfully completed.

FIG. 13 is an example structure for MAC entities as per an aspect of anembodiment. In an example, a wireless device may be configured tooperate in a multi-connectivity mode. A wireless device in RRC_CONNECTEDwith multiple RX/TX may be configured to utilize radio resourcesprovided by multiple schedulers located in a plurality of base stations.The plurality of base stations may be connected via a non-ideal or idealbackhaul over the Xn interface. In an example, a base station in aplurality of base stations may act as a master base station or as asecondary base station. A wireless device may be connected to one masterbase station and one or more secondary base stations. A wireless devicemay be configured with multiple MAC entities, e.g. one MAC entity formaster base station, and one or more other MAC entities for secondarybase station(s). In an example, a configured set of serving cells for awireless device may comprise two subsets: an MCG comprising servingcells of a master base station, and one or more SCGs comprising servingcells of a secondary base station(s). FIG. 13 illustrates an examplestructure for MAC entities when MCG and SCG are configured for awireless device.

In an example, at least one cell in a SCG may have a configured UL CC,wherein a cell of at least one cell may be called PSCell or PCell ofSCG, or sometimes may be simply called PCell. A PSCell may be configuredwith PUCCH resources. In an example, when a SCG is configured, there maybe at least one SCG bearer or one split bearer. In an example, upondetection of a physical layer problem or a random access problem on aPSCell, or upon reaching a number of RLC retransmissions associated withthe SCG, or upon detection of an access problem on a PSCell during a SCGaddition or a SCG change: an RRC connection reestablishment proceduremay not be triggered, UL transmissions towards cells of an SCG may bestopped, a master base station may be informed by a UE of a SCG failuretype and DL data transfer over a master base station may be maintained.

In an example, a MAC sublayer may provide services such as data transferand radio resource allocation to upper layers (e.g. 1310 or 1320). A MACsublayer may comprise a plurality of MAC entities (e.g. 1350 and 1360).A MAC sublayer may provide data transfer services on logical channels.To accommodate different kinds of data transfer services, multiple typesof logical channels may be defined. A logical channel may supporttransfer of a particular type of information. A logical channel type maybe defined by what type of information (e.g., control or data) istransferred. For example, BCCH, PCCH, CCCH and DCCH may be controlchannels and DTCH may be a traffic channel. In an example, a first MACentity (e.g. 1310) may provide services on PCCH, BCCH, CCCH, DCCH, DTCHand MAC control elements. In an example, a second MAC entity (e.g. 1320)may provide services on BCCH, DCCH, DTCH and MAC control elements.

A MAC sublayer may expect from a physical layer (e.g. 1330 or 1340)services such as data transfer services, signaling of HARQ feedback,signaling of scheduling request or measurements (e.g. CQI). In anexample, in dual connectivity, two MAC entities may be configured for awireless device: one for MCG and one for SCG. A MAC entity of wirelessdevice may handle a plurality of transport channels. In an example, afirst MAC entity may handle first transport channels comprising a PCCHof MCG, a first BCH of MCG, one or more first DL-SCHs of MCG, one ormore first UL-SCHs of MCG and one or more first RACHs of MCG. In anexample, a second MAC entity may handle second transport channelscomprising a second BCH of SCG, one or more second DL-SCHs of SCG, oneor more second UL-SCHs of SCG and one or more second RACHs of SCG.

In an example, if a MAC entity is configured with one or more SCells,there may be multiple DL-SCHs and there may be multiple UL-SCHs as wellas multiple RACHs per MAC entity. In an example, there may be one DL-SCHand UL-SCH on a SpCell. In an example, there may be one DL-SCH, zero orone UL-SCH and zero or one RACH for an SCell. A DL-SCH may supportreceptions using different numerologies and/or TTI duration within a MACentity. A UL-SCH may also support transmissions using differentnumerologies and/or TTI duration within the MAC entity.

In an example, a MAC sublayer may support different functions and maycontrol these functions with a control (e.g. 1355 or 1365) element.Functions performed by a MAC entity may comprise mapping between logicalchannels and transport channels (e.g., in uplink or downlink),multiplexing (e.g. 1352 or 1362) of MAC SDUs from one or differentlogical channels onto transport blocks (TB) to be delivered to thephysical layer on transport channels (e.g., in uplink), demultiplexing(e.g. 1352 or 1362) of MAC SDUs to one or different logical channelsfrom transport blocks (TB) delivered from the physical layer ontransport channels (e.g., in downlink), scheduling information reporting(e.g., in uplink), error correction through HARQ in uplink or downlink(e.g. 1363), and logical channel prioritization in uplink (e.g. 1351 or1361). A MAC entity may handle a random access process (e.g. 1354 or1364).

FIG. 14 is an example diagram of a RAN architecture comprising one ormore base stations. In an example, a protocol stack (e.g. RRC, SDAP,PDCP, RLC, MAC, and PHY) may be supported at a node. A base station(e.g. gNB 120A or 120B) may comprise a base station central unit (CU)(e.g. gNB-CU 1420A or 1420B) and at least one base station distributedunit (DU) (e.g. gNB-DU 1430A, 1430B, 1430C, or 1430D) if a functionalsplit is configured. Upper protocol layers of a base station may belocated in a base station CU, and lower layers of the base station maybe located in the base station DUs. An F1 interface (e.g. CU-DUinterface) connecting a base station CU and base station DUs may be anideal or non-ideal backhaul. F1-C may provide a control plane connectionover an F1 interface, and F1-U may provide a user plane connection overthe F1 interface. In an example, an Xn interface may be configuredbetween base station CUs.

In an example, a base station CU may comprise an RRC function, an SDAPlayer, and a PDCP layer, and base station DUs may comprise an RLC layer,a MAC layer, and a PHY layer. In an example, various functional splitoptions between a base station CU and base station DUs may be possibleby locating different combinations of upper protocol layers (RANfunctions) in a base station CU and different combinations of lowerprotocol layers (RAN functions) in base station DUs. A functional splitmay support flexibility to move protocol layers between a base stationCU and base station DUs depending on service requirements and/or networkenvironments.

In an example, functional split options may be configured per basestation, per base station CU, per base station DU, per UE, per bearer,per slice, or with other granularities. In per base station CU split, abase station CU may have a fixed split option, and base station DUs maybe configured to match a split option of a base station CU. In per basestation DU split, a base station DU may be configured with a differentsplit option, and a base station CU may provide different split optionsfor different base station DUs. In per UE split, a base station (basestation CU and at least one base station DUs) may provide differentsplit options for different wireless devices. In per bearer split,different split options may be utilized for different bearers. In perslice splice, different split options may be applied for differentslices.

FIG. 15 is an example diagram showing RRC state transitions of awireless device. In an example, a wireless device may be in at least oneRRC state among an RRC connected state (e.g. RRC Connected 1530,RRC_Connected), an RRC idle state (e.g. RRC Idle 1510, RRC_Idle), and/oran RRC inactive state (e.g. RRC Inactive 1520, RRC_Inactive). In anexample, in an RRC connected state, a wireless device may have at leastone RRC connection with at least one base station (e.g. gNB and/or eNB),which may have a UE context of the wireless device. A UE context (e.g. awireless device context) may comprise at least one of an access stratumcontext, one or more radio link configuration parameters, bearer (e.g.data radio bearer (DRB), signaling radio bearer (SRB), logical channel,QoS flow, PDU session, and/or the like) configuration information,security information, PHY/MAC/RLC/PDCP/SDAP layer configurationinformation, and/or the like configuration information for a wirelessdevice. In an example, in an RRC idle state, a wireless device may nothave an RRC connection with a base station, and a UE context of awireless device may not be stored in a base station. In an example, inan RRC inactive state, a wireless device may not have an RRC connectionwith a base station. A UE context of a wireless device may be stored ina base station, which may be called as an anchor base station (e.g. lastserving base station).

In an example, a wireless device may transition a UE RRC state betweenan RRC idle state and an RRC connected state in both ways (e.g.connection release 1540 or connection establishment 1550; or connectionreestablishment) and/or between an RRC inactive state and an RRCconnected state in both ways (e.g. connection inactivation 1570 orconnection resume 1580). In an example, a wireless device may transitionits RRC state from an RRC inactive state to an RRC idle state (e.g.connection release 1560).

In an example, an anchor base station may be a base station that maykeep a UE context (a wireless device context) of a wireless device atleast during a time period that a wireless device stays in a RANnotification area (RNA) of an anchor base station, and/or that awireless device stays in an RRC inactive state. In an example, an anchorbase station may be a base station that a wireless device in an RRCinactive state was lastly connected to in a latest RRC connected stateor that a wireless device lastly performed an RNA update procedure in.In an example, an RNA may comprise one or more cells operated by one ormore base stations. In an example, a base station may belong to one ormore RNAs. In an example, a cell may belong to one or more RNAs.

In an example, a wireless device may transition a UE RRC state from anRRC connected state to an RRC inactive state in a base station. Awireless device may receive RNA information from the base station. RNAinformation may comprise at least one of an RNA identifier, one or morecell identifiers of one or more cells of an RNA, a base stationidentifier, an IP address of the base station, an AS context identifierof the wireless device, a resume identifier, and/or the like.

In an example, an anchor base station may broadcast a message (e.g. RANpaging message) to base stations of an RNA to reach to a wireless devicein an RRC inactive state, and/or the base stations receiving the messagefrom the anchor base station may broadcast and/or multicast anothermessage (e.g. paging message) to wireless devices in their coveragearea, cell coverage area, and/or beam coverage area associated with theRNA through an air interface.

In an example, when a wireless device in an RRC inactive state movesinto a new RNA, the wireless device may perform an RNA update (RNAU)procedure, which may comprise a random access procedure by the wirelessdevice and/or a UE context retrieve procedure. A UE context retrieve maycomprise: receiving, by a base station from a wireless device, a randomaccess preamble; and fetching, by a base station, a UE context of thewireless device from an old anchor base station. Fetching may comprise:sending a retrieve UE context request message comprising a resumeidentifier to the old anchor base station and receiving a retrieve UEcontext response message comprising the UE context of the wirelessdevice from the old anchor base station.

In an example embodiment, a wireless device in an RRC inactive state mayselect a cell to camp on based on at least a on measurement results forone or more cells, a cell where a wireless device may monitor an RNApaging message and/or a core network paging message from a base station.In an example, a wireless device in an RRC inactive state may select acell to perform a random access procedure to resume an RRC connectionand/or to transmit one or more packets to a base station (e.g. to anetwork). In an example, if a cell selected belongs to a different RNAfrom an RNA for a wireless device in an RRC inactive state, the wirelessdevice may initiate a random access procedure to perform an RNA updateprocedure. In an example, if a wireless device in an RRC inactive statehas one or more packets, in a buffer, to transmit to a network, thewireless device may initiate a random access procedure to transmit oneor more packets to a base station of a cell that the wireless deviceselects. A random access procedure may be performed with two messages(e.g. 2 stage random access) and/or four messages (e.g. 4 stage randomaccess) between the wireless device and the base station.

In an example embodiment, a base station receiving one or more uplinkpackets from a wireless device in an RRC inactive state may fetch a UEcontext of a wireless device by transmitting a retrieve UE contextrequest message for the wireless device to an anchor base station of thewireless device based on at least one of an AS context identifier, anRNA identifier, a base station identifier, a resume identifier, and/or acell identifier received from the wireless device. In response tofetching a UE context, a base station may transmit a path switch requestfor a wireless device to a core network entity (e.g. AMF, MME, and/orthe like). A core network entity may update a downlink tunnel endpointidentifier for one or more bearers established for the wireless devicebetween a user plane core network entity (e.g. UPF, S-GW, and/or thelike) and a RAN node (e.g. the base station), e.g. changing a downlinktunnel endpoint identifier from an address of the anchor base station toan address of the base station.

In an implementation of existing technologies, a wireless device mayaccess a cell without a random access procedure (e.g., RACH-less and/orRACH-skip) if the wireless device knows a timing advance (TA) for thecell. A network (e.g., a base station) may provide a TA of a cell (e.g.,cell specific TA) for a wireless device, and/or the wireless device maytransmit a transport block via a physical uplink shared channel (PUSCH)based on the TA without performing a random access process. If a celloperates with multiple transmission reception points (TRPs) (e.g.,reception points), a TA may have a different value depending on whichTRP receives signal from a wireless device. In an existing technology,if a wireless device attempts to access a cell configured with multipleTRPs without a random access procedure based on a single TA (e.g., cellspecific TA) for the cell, the wireless device may fail in the accessattempt depending on a TRP that receives a signal for the accessattempt. An access failure caused by an improper TA in RACH-less accessprocedure (e.g., handover and/or secondary cell group change procedure)may decrease communication reliability and increase service delay.Enhanced signaling mechanisms for RACH-less access of wireless devicesare needed.

Embodiments of the present disclosure may provide enhanced signalingmechanisms for wireless devices that access a cell (e.g., for handoverand/or secondary cell group change) without a random access procedure.In an example embodiment, a network (e.g., a base station) may providemultiple TAs (e.g., and/or at least onebeam/beam-group/TRP/TAG/CORESET/CORESET-group/TCI-state specific TA) fora wireless device that accesses a cell using multiple TRPs. Each of themultiple TAs (e.g., and/or the at least onebeam/beam-group/TRP/TAG/CORESET/CORESET-group/TCI-state specific TA) maybe associated with one or more beams, a TRP, a timing advance group(TAG), and/or the like. The wireless device may use one of the multipleTAs to access the cell, depending on which downlink beam (e.g., TRPand/or TAG) is selected for the access. Example embodiments may increasecommunication reliability and decrease service latency.

In an example, as shown in FIG. 16 , FIG. 20 , and/or FIG. 22 , awireless device (e.g., user equipment, UE, device, etc.) may be servedby a second base station (e.g., gNB2, gNB, eNB, access node, accessnetwork, etc.). The second base station may have a connection with afirst base station (e.g., gNB1, gNB, eNB, access node, access network,etc.). The connection may comprise a direct connection (e.g., Xninterface, X2 interface, etc.) and/or an indirect connection (e.g.,comprising one or more N2 or S1 interfaces) via one or more core networknodes (e.g., AMF, MME, etc.). The first base station may serve a firstcell. The first cell may comprise (e.g., operate based on) a pluralityof beams comprising a first beam and/or a second beam. In an example,the first cell may use multiple transmission reception points (TRPs)(e.g., comprising a transmission point (TP) and/or a reception point(RP)) comprising a first TRP and/or a second TRP. A first base stationdistributed unit (e.g., gNB-DU1, gNB-DU, base station DU, DU, etc.) ofthe first base station may comprise the first TRP. A second base stationdistributed unit (e.g., gNB-DU2, gNB-DU, base station DU, DU, etc.) ofthe first base station may comprise the second TRP. In an example, thefirst TRP may serve (e.g., transmit) the first beam, and/or the secondTRP may serve (e.g., transmit) the second beam. In the presentdisclosure, the first base station may be interpreted as a base stationcentral unit (e.g., gNB-CU, base station CU, CU, etc.) of the first basestation.

In an example, as shown in FIG. 18 , the first base station may be thesecond base station. In an example, the first base station may be asecondary base station (e.g., SgNB, SeNB, secondary node, S-node, etc.)serving a secondary cell group (SCG) of the wireless device. The secondbase station may be a master base station (e.g., MgNB, MeNB, masternode, M-node, etc.) serving a master cell group (MCG) of the wirelessdevice. By performing a handover to the first cell of the first basestation, the wireless device may change/update the first base stationfrom a secondary base station to a master base station.

In an example, a wireless device may receive, from a second basestation, a radio resource control message comprising access informationfor a first cell of a first base station. The access information mayindicate a first timing advance associated with a first beam of thefirst cell. The wireless device may determine/select the first beam toaccess the first cell. The wireless device may transmit, based on thedetermining the first beam, transport blocks based on the first timingadvance to access the first cell.

In an example, the wireless device may receive, from the second basestation, a radio resource control (RRC) message comprising accessinformation for the first cell of the first base station. The accessinformation may indicate a first timing advance (TA) associated with thefirst beam of the first cell and a second TA associated with the secondbeam of the first cell. The wireless device may determine one of thefirst beam and the second beam as a selected beam. The wireless devicemay select a selected TA (e.g., among the first TA and the second TA)associated with the selected beam. The selected TA may be one of thefirst TA and the second TA. The wireless device may transmit transportblocks based on the selected TA to access the first cell.

In an example, the first base station may transmit the first beam andthe second beam via the first cell. The wireless device maysend/transmit, to the second base station, at least one measurementreport comprising measurement results of the first cell (e.g.,measurement results of the first beam and/or the second beam). Thesecond base station may determine, based on the at least one measurementreport, a handover (e.g., or a secondary node addition/modification) ofthe wireless device to the first cell of the first base station. Thesecond base station may send, to the first base station, a requestmessage for the handover (e.g., or the secondary nodeaddition/modification) of the wireless device. The first base stationmay determine, based on the request message, access information for thewireless device. The access information may indicate a first TAassociated with the first beam of the first cell and a second TAassociated with the second beam of the first cell. The first basestation may send, to the second base station and in response to therequest message, a request acknowledge message (e.g., a handover requestacknowledge message or a secondary base station addition/modificationrequest acknowledge message) comprising the access information for thefirst cell. The second base station may send, to the wireless device, anRRC message (e.g., a handover command or an RRC reconfiguration message)comprising the access information. The wireless device may determine oneof the first beam and the second beam as a selected beam. The wirelessdevice may select a selected TA (e.g., among the first TA and the secondTA) associated with the selected beam. The selected TA may be one of thefirst TA and the second TA. The wireless device may transmit transportblocks based on the selected TA to access the first cell.

In an example, as shown in FIG. 17 , FIG. 19 , FIG. 21 , and/or FIG. 23, the first base station may transmit the first beam and the second beamvia the first cell. In an example, the first cell may comprise the firstbeam and the second beam. The first beam and/or the second beam may beassociated with at least one of: a channel state information-referencesignal (CSI-RS); a synchronization signal (SS); a reference signal,and/or the like. In an example, the first beam may be transmitted by thefirst TRP. The second beam may be transmitted by the second TRP. In anexample, the first beam may be transmitted by the first base stationdistributed unit of the first base station. The second beam may betransmitted by the second base station distributed unit of the firstbase station.

In an example, the wireless device may receive, from the first basestation, at least one of: the first beam (e.g., SS or CSI-RS); thesecond beam (e.g., SS or CSI-RS); the at least one third beam; and/orthe like. The wireless device may receive, from the second base station,a measurement configuration (e.g., meas-Config, via an RRCreconfiguration message) comprising beam configuration parameters (e.g.,beam transmission timing, frequency, periodicity, etc.) of the firstbeam and/or the second beam. The wireless device may receive, based onthe measurement configuration, a SS and/or a CSI-RS associated with thefirst beam and/or receive a SS and/or a CSI-RS associated with thesecond beam. The wireless device may measure a received quality and/or areceived power of the first beam, the second beam, the at least onethird beam; and/or the like.

In an example, the wireless device may send/transmit, to the second basestation, at least one measurement report comprising measurement resultsof the first cell (e.g., measurement results of the first beam and/orthe second beam). In an example, the wireless device may send/transmitthe at least one measurement report based on the receiving the firstbeam (e.g., SS or CSI-RS) and/or the second beam (e.g., SS or CSI-RS).The measurement results may comprise at least one of: a first receivedpower (e.g., first RSRP) of the first beam (e.g., SS or CSI-RS); a firstreceived quality (e.g., first RSRQ) of the first beam (e.g., SS orCSI-RS); a second received power (e.g., second RSRP) of the second beam(e.g., SS or CSI-RS); a second received quality (e.g., second RSRQ) ofthe second beam (e.g., SS or CSI-RS); a third received power of the atleast one third beam (e.g., SS or CSI-RS); a third received quality ofthe at least one third beam (e.g., SS or CSI-RS); and/or the like. Themeasurement results may comprise a combined RSRP and/or a combined RSRQ(e.g., layer 3 measurement result) of one or more beams (e.g., the firstbeam and/or the second beam) of the first cell. The combined RSRP may bean RSRP of the first cell. The combined RSRQ may be an RSRQ of the firstcell. The measurement results may comprise one or more RSRPs and/or oneor more RSRQs of one or more cells of the first base station and/or thesecond base station. In an example, the at least one measurement reportmay comprise an RRC layer message.

In an example, the second base station may determine, based on the atleast one measurement report, a radio resource configuration initiation(e.g., a handover or a secondary node addition/modification) of thefirst cell of the first base station for the wireless device. The radioresource configuration initiation may be at least one of: the handoverof the wireless device to the first cell; the secondary nodeaddition/modification (e.g., secondary node addition or secondary nodemodification) for the wireless device with the first base station (e.g.,configuring the first cell as a secondary cell group (SCG): a primarysecondary cell (PScell) and/or a secondary cell (Scell) of the wirelessdevice); and/or the like. The secondary node addition/modificationprocedure may be and/or may be part of an SCG change procedure.

In an example, the second base station may determine, based on the atleast one measurement report, the handover of the wireless device to thefirst cell. In an example, the second base station may determine, basedon the at least one measurement report, a secondary node configuration(e.g., the secondary node addition/modification) for the wirelessdevice. The secondary node configuration may comprise configuring thefirst cell as an SCG for the wireless device.

In an example, based on determining the radio resource configurationinitiation, the second base station may send, to the first base station,a request message for the radio resource configuration initiation (e.g.,the handover or the secondary node addition/modification) of thewireless device. The request message may be a handover request messagefor the handover of the wireless device. The request message may be, forthe secondary node addition/modification of the wireless device, atleast one of: a secondary node addition request message (e.g., S-nodeaddition request message, SeNB addition request message, etc.); asecondary node modification request message (e.g., S-node modificationrequest message, SeNB modification request message, etc.); and/or thelike. In an example, the second base station may send, to the first basestation, the handover request message for the handover of the wirelessdevice. In an example, the second base station may send, to the firstbase station, a configuration request message (e.g., the secondary nodeaddition request message or the secondary node modification requestmessage) for the secondary node configuration (e.g., the secondary nodeaddition/modification) for the wireless device.

In an example, the second base station may send the request message tothe first base station via the direct interface (e.g., the Xn interfaceand/or the X2 interface) between the first base station and the secondbase station. In an example, the second base station may send indicationof the request of the radio resource configuration initiation (e.g., thehandover or the secondary node addition/modification) via the indirectconnection (e.g., comprising the one or more N2 or S1 interfaces)through the one or more core network nodes (e.g., AMF, MME, etc.). In anexample, the second base station may send, to the AMF, a handoverrequired message for the handover of the wireless device, and/or the AMFmay send, to the first base station and based on the handover requiredmessage, an S1/N2 handover request message for the handover of thewireless device.

In an example, the request message may comprise the measurement resultsof the at least one measurement report. The request message may compriseat least one of: a UE identifier of the wireless device; a cellidentifier (e.g., physical cell identifier, PCI, cell global identifier,CGI, etc.) of the first cell (e.g., target cell); security capabilityinformation and/or security information of the wireless device; PDUsession information (e.g., PDU session list, QoS flow list, QoS,S-NSSAI, NSSAI, etc.) of the wireless device; RRC contexts (e.g., RRCconfiguration parameters; e.g., recommended RRC configurationparameters) of the wireless device; and/or the like.

In an example, the first base station may determine, based on therequest message, access information for the wireless device to accessthe first cell. The access information may indicate a TA for at leastone of: one or more beams, a TRP, a TAG, a CORESET, a CORESET group, atleast one TCI state, at least one QCL, at least one QCL type, and/or thelike. The access information may be for the wireless device to accessthe first cell. The access information may indicate a first TAassociated with the first beam (e.g., and/or first TRP, first TAG, firstCORESET(s), first TCI-state(s), first QCL-type, etc.) of the first celland/or a second TA associated with the second beam (e.g., and/or secondTRP, second TAG, second CORESET(s), second TCI-state(s), secondQCL-type, etc.) of the first cell. In an example, the first TA may bedifferent than the second TA. The wireless device may use at least oneof the first TA and/or the second TA to access the first cell for thehandover and/or the secondary base station addition/modification.

In an example, the first TA and/or the second TA may comprise at leastone of: a zero TA (e.g., TA=0); a TA of a primary timing advance group(TAG) of a master cell group (MCG) of the wireless device; a TA of asecondary TAG of a master cell group (MCG) of the wireless device; a TAof a primary TAG of a secondary cell group (SCG) of the wireless device;a TA of a secondary TAG of a secondary cell group (SCG) of the wirelessdevice; and/or the like.

In an example, the access information may indicate, for the first TAand/or the second TA, at least one of: a TA is zero (e.g., ta0); aprimary TAG of an MCG; a secondary TAG (e.g., a TAG identifier of thesecondary TAG) of an MCG; a primary TAG of an SCG; and/or a secondaryTAG (e.g., a TAG identifier of the secondary TAG) of an SCG. In anexample, the primary TAG of the MCG (e.g., mcg-PTAG) in the accessinformation may indicate that the first TA and/or the second TA is same(e.g., close) to a TA of the primary TAG of the MCG that the wirelessdevice is configured with at the time of the radio resourceconfiguration initiation. In an example, the secondary TAG of the MCG(e.g., mcg-STAG) in the access information may indicate that the firstTA and/or the second TA is same (e.g., close) to a TA of the secondaryTAG of the MCG that the wireless device is configured with at the timeof the radio resource configuration initiation. The secondary TAG of theMCG may further indicate a secondary TAG identifier indicating at leastone of one or more secondary TAGs of the MCG of the wireless device. Inan example, the primary TAG of the SCG (e.g., scg-PTAG) in the accessinformation may indicate that the first TA and/or the second TA is same(e.g., close) to a TA of the primary TAG of the SCG that the wirelessdevice is configured with at the time of the radio resourceconfiguration initiation. In an example, the secondary TAG of the SCG(e.g., scg-STAG) in the access information may indicate that the firstTA and/or the second TA is same (e.g., close) to a TA of the secondaryTAG of the SCG that the wireless device is configured with at the timeof the radio resource configuration initiation. The secondary TAG of theSCG may further indicate a secondary TAG identifier indicating at leastone of one or more secondary TAGs of the SCG of the wireless device. Inan example implementation, the access information may indicate that a TAof the first TA is zero and that a TA of the second TA is same to theprimary TAG of the SCG. In an example, the access information maycomprise at least one of: a fist value (e.g., integer value 0, ..., 63;e.g., 6 bits) of the first TA; and/or a second value (e.g., integervalue 0, ..., 63; e.g., 6 bits) of the second TA. FIG. 26 shows anexample information element of the access information indicating thefirst TA and/or the second TA.

In an example, the access information may comprise first fields forfirst resources associated with the first beam. The first fields maycomprise at least one of: a first number of configured hybrid automaticrepeat request (HARQ) processes (e.g., numberOfConfUL-Processes); afirst uplink grant (e.g., ul-Grant); a first uplink scheduling interval(e.g., ul-SchedInterval); a first uplink starting subframe/slot/symbol(e.g., ul-StartSubframe, ul-Slot, ul-Symbol, etc.); and/or the like. Inan example, the access information may comprise second fields for secondresources associated with the second beam. The second fields maycomprise at least one of: a second number of configured HARQ processes(e.g., numberOfConfUL-Processes); a second uplink grant (e.g.,ul-Grant); a second uplink scheduling interval (e.g., ul-SchedInterval);a second uplink starting subframe/slot/symbol (e.g., ul-StartSubframe,ul-Slot, ul-Symbol, etc.); and/or the like. In an example, the wirelessdevice may transmit transport blocks via the first resources or thesecond resources associated with a selected beam (e.g., the first beamor the second beam) to access the first cell. FIG. 26 shows an exampleinformation element of the access information indicating the firstresources associated with the first beam (e.g., and/or first TRP, firstTAG, first CORESET(s), first TCI-state(s), first QCL-type, etc.) and/orthe second resources associated with the second beam (e.g., and/orsecond TRP, second TAG, second CORESET(s), second TCI-state(s), secondQCL-type, etc.). In an example, the access information may indicate thatthe first TA is associated with the first resources (e.g., indicate thatthe wireless device may need to apply the first TA when the wirelessdevice uses the first resources for transmission of transport blocks toaccess the first cell). In an example, the access information mayindicate that the second TA is associated with the second resources(e.g., indicate that the wireless device may need to apply the second TAwhen the wireless device uses the second resources for transmission oftransport blocks to access the first cell).

In an example, the first and/or second number of configured HARQprocesses (e.g., numberOfConfUL-Processes) may be a number of configuredHARQ processes for pre-allocated uplink grant for the wireless device(e.g., when the wireless device is configured with asynchronous HARQ).In an example, the first and/or second uplink grant (e.g., ul-Grant) mayindicate resources of a target PCell/PSCell (e.g., the first cell) to beused for uplink transmission of PUSCH (e.g., transport blocks). In anexample, the first and/or second uplink scheduling interval (e.g.,ul-SchedInterval) may indicate a scheduling interval in uplink, and/ormay indicate a number of subframes/slots/symbols. Value sf2 maycorresponds to 2 subframes, sf5 may correspond to 5 subframes, slot2 maycorresponds to 2 slots, symbol2 may corresponds to 2 symbols (e.g., OFDMsymbols), and/or the like. In an example, the first and/or second uplinkstarting subframe/slot/symbol (e.g., ul-StartSubframe, ul-Slot,ul-Symbol, etc.) may indicate a subframe/slot/symbol in which thewireless device may initiate an uplink transmission (e.g., transmissionof transport blocks of PUSCH). Value 0 may correspond tosubframe/slot/symbol number 0, 1 may correspond to subframe/slot/symbolnumber 1, and/or the like. A subframe/slot/symbol indicating a validuplink grant according to calculation/determination of UL grantconfigured by ul-StartSubframe/Slot/Symbol and/or ul-SchedInterval/ maybe the same across radio frames.

In an example, as shown in FIG. 26 , the access information may compriseat least one of: a beam index of the first beam (e.g., at least oneSSB-Index, at least one CSI-RS-Index); an identifier of a first TRP(e.g., TRP-Index) associated with the first beam and/or the first TA; agroup identifier of a first CORESET group (e.g., CORESET-Id and/orCORESET-Group-Id) associated with the first TRP and/or the first TA; anidentifier of a first TCI state (e.g., at least one TCI-StateId)associated with the first TRP and/or the first TA; a first QCL typeassociated with the first TRP and/or the first TA; and/or the like. Inan example, the access information may comprise at least one of: a beamindex of the second beam (e.g., at least one SSB-Index, at least oneCSI-RS-Index); an identifier of a second TRP (e.g., TRP-Index)associated with the second beam and/or the second TA; a group identifierof a second CORESET group (e.g., CORESET-Id and/or CORESET-Group-Id)associated with the second TRP and/or the second TA; an identifier of asecond TCI state (e.g., at least one TCI-StateId) associated with thesecond TRP and/or the second TA; a second QCL type associated with thesecond TRP and/or the second TA; and/or the like.

In an example, the access information may comprise at least one of: anidentifier of a first TAG (e.g., PTAG, STAG-ID: STAG1, STAG2, STAG3,STAG4, ...) associated with the first beam and/or the first TA; and/oran identifier of a second TAG (e.g., PTAG, STAG-ID: STAG1, STAG2, STAG3,STAG4, ...) associated with the second beam and/or the second TA. In anexample, the first TAG and/or the second TAG may be a TAG when the whenthe first base station serves the wireless device and/or when/after theradio resource configuration initiation (e.g., the handover or thesecondary node addition/modification) of the wireless device for thefirst cell is completed. In an example, the first TAG and/or the secondTAG may be configured based on at least one of: one or more cells; oneor more TRPs; one or more beams (e.g., SSB, CSI-RS beam); one or moreCORESET groups; one or more TCI states; and/or the like.

In an example implementation, the first TAG may comprise (e.g., consistof) the first cell, a second cell, and a third cell. In an exampleimplementation, the first TAG may comprise (e.g., consist of) the firstbeam of the first cell and a third beam of the first cell. In an exampleimplementation, the first TAG may comprise (e.g., consist of) the firstbeam of the first cell and a second cell. In an example implementation,the second TAG may comprise (e.g., consist of) the first cell, a fourthcell, and a fifth cell. In an example implementation, the second TAG maycomprise (e.g., consist of) the second beam of the first cell and afourth beam of the first cell. In an example implementation, the secondTAG may comprise (e.g., consist of) the second beam of the first celland a fourth cell. In an example, the first TAG may comprise one or morebeams and/or one or more cells served by a first TRP. In an example, thesecond TAG may comprise one or more beams and/or one or more cellsserved by a second TRP. In an example, the first TRP may comprise afirst CORESET group of the first cell, and/or the second TRP maycomprise a second CORESET group of the first cell. In an example, thefirst TRP may comprise at least one first TCI state for the first cell,and/or the second TRP may comprise at least one second TCI state for thefirst cell. FIG. 27 shows an example TA grouping of the wireless devicefor the first TAG (e.g., TAG1) associated with first TA and the secondTAG (TAG2) associated with the second TA.

In an example, the access information may comprise random accessconfiguration parameters associated with at least one third beam (e.g.,SSB, CSI-RS) (e.g., The at least one third beam may comprise the firstbeam and/or the second beam) for the wireless device to access the firstcell. The random access configuration parameters may comprise at leastone of: a beam index; a random access preamble index (e.g., integervalue 0 to 63) of a random access preamble; at least one random accessoccasion (e.g., for CSI-RS); a reference signal received power (RSRP)value (e.g., threshold) indicating a range of received power (e.g., toperform a contention free random access procedure). In an example, theat least one third beam may be transmitted by a third TRP (e.g., thethird TRP may be one of the first TRP or the second TRP). In an example,if an RSRP of the at least one third beam is in the range of receivedpower indicated by the RSRP value, the wireless device may perform arandom access using the random access preamble and/or the at least onerandom access occasion for the at least one third beam. In an example,if an RSRP of the at least one third beam is in the range of receivedpower indicated by the RSRP value, the wireless device may perform acontention based random access to access the first cell.

In an example, the access information may comprise a power value for thewireless device to determine initiation of a random access using therandom access configuration parameters (e.g., instead of RACH-lessaccess for the first cell; instead of transmitting transport blocks ofPUSCH to access the first cell). The wireless device may compare thepower value with a received power of the first beam and/or the secondbeam for the initiation of the random access using the random accessconfiguration parameters. In an example, the access information maycomprise a time value for the wireless device to determine initiation ofa random access using the random access configuration parameters. Thewireless device may initiate the random access (e.g., by transmitting arandom access preamble) in response to a time duration of the time valuepassing (e.g., in response to expiry of the time duration)since/from/after the first signal (e.g., one of the transport blocks,PUSCH, random access preamble, and/or the like to access the first cell)transmission to the first base station. In an example, a random accessusing the random access configuration parameters may comprise at leastone of: a contention-free random access; a contention-based randomaccess; and/or the like. In an example, a random access using the randomaccess configuration parameters may comprise at least one of: a 2-steprandom access; a 4-step random access; and/or the like. The accessinformation may comprise a power value (e.g., threshold) for selectionof the 2-step random access or the 4 step random access.

In an example, the access information may indicate a second time value.The second time value may be a time duration that a TA indicated by theaccess information is valid. After a time duration of the second timevalue (e.g., from receiving a handover command), the wireless device mayinitiate a random access (e.g., instead of transmitting transport blocksvia PUSCH to access the first cell) for the first cell.

In an example, the access information may indicate at least one of: afirst panel of the wireless device for transmission associated with thefirst beam; a second panel of the wireless device for transmissionassociated with the second beam; and/or the like. The wireless devicemay use the first panel of the wireless device to transmit the transportblocks to access the first cell, in response to the selected beam beingthe first beam. The wireless device may use the second panel of thewireless device to transmit the transport blocks to access the firstcell, in response to the selected beam being the second beam.

In an example, the access information may be determined by at least oneof: the first base station (e.g., for a handover and/or a secondary basestation addition/modification of the wireless device) and/or the secondbase station (e.g., for a secondary base station addition/modificationof the wireless device).

In an example, the first base station may send, to the second basestation and in response to the request message and/or in response todetermining to accept the request for the radio resource configurationinitiation (e.g., the handover or the secondary nodeaddition/modification) of the wireless device, a request acknowledgemessage (e.g., a handover request acknowledge message or a secondarybase station addition/modification request acknowledge message)comprising the access information for the first cell. In an example, thesecond base station may receive, from the first base station, a handoverrequest acknowledge message (e.g., for the handover) comprising theaccess information for the first cell. In an example, the second basestation may receive, from the first base station, a configurationrequest acknowledge message (e.g., for the secondary nodeaddition/modification) comprising the access information for the firstcell. The configuration request acknowledge message may comprise atleast one of: a secondary node addition request acknowledge message(e.g., S-node addition request acknowledge message, SeNB additionrequest acknowledge message, etc.); a secondary node modificationrequest acknowledge message (e.g., S-node modification requestacknowledge message, SeNB modification request acknowledge message,etc.); and/or the like.

In an example, the first base station may send the request acknowledgemessage to the second base station via the direct interface (e.g., theXn interface and/or the X2 interface) between the first base station andthe second base station. In an example, the first base station may sendindication of the request acknowledge of the radio resourceconfiguration initiation (e.g., the handover or the secondary nodeaddition/modification) via the indirect connection (e.g., comprising theone or more N2 or S1 interfaces) through the one or more core networknodes (e.g., AMF, MME, etc.). In an example, the first base station maysend, to the AMF, an S1/N2 handover request acknowledge message for thehandover of the wireless device, and/or the AMF may send, to the secondbase station and based on the handover request acknowledge message, anS1/N2 handover command message for the handover of the wireless device.

In an example, the request acknowledge message may comprise at least oneof: a UE identifier of the wireless device; a cell identifier (e.g.,physical cell identifier, PCI, cell global identifier, CGI, etc.) of thefirst cell (e.g., target cell); security capability information and/orsecurity information of the wireless device; PDU session information(e.g., accepted/setup/modified/rejected/released PDU session list, QoSflow list, QoS, S-NSSAI, NSSAI, etc.) of the wireless device; RRCcontexts (e.g., RRC configuration parameters that may be configuredbased on the measurement results of the wireless device for the firstcell) of the wireless device; and/or the like.

In an example, the second base station may send, to the wireless deviceand/or based on the request acknowledge message, an RRC message (e.g., ahandover command message (e.g., a handover command) and/or an RRCreconfiguration message) comprising the access information. In anexample, the RRC message may comprise at least one of: a handovercommand message; an RRC reconfiguration message; and/or the like. In anexample, the handover command message may be configured by the firstbase station, and the first base station may forward the handovercommand to the wireless device. The RRC message (e.g., the handovercommand message and/or the RRC reconfiguration message) may be based onthe handover request acknowledge message. The handover requestacknowledge message may comprise the RRC reconfiguration message (e.g.,comprising the access information) that is the handover command message.The RRC message (e.g., the RRC reconfiguration message) may be based onthe configuration request acknowledge message (e.g., the secondary nodeaddition request acknowledge message, the secondary node modificationrequest acknowledge message).

In an example, the handover command message may indicate a condition forthe wireless device to initiate an access to the first cell. Thecondition may comprise an initiation power value. In an example, when areceived power of the first cell (e.g., or at least one of the firstbeam or the second beam) becomes/is equal to or higher than theinitiation power value, the wireless device may send signal (e.g.,transport blocks via PUSCH to access the first cell, and/or preamble forrandom access) to the first base station. In an example, if the secondbase station determines the access information, the second base stationmay include the access information in the RRC message (e.g., the RRCreconfiguration message).

In an example, the wireless device may determine one of the first beamand the second beam as a selected beam to access the first cell. Thewireless device may select, based on the access information, a selectedTA (e.g., among the first TA and the second TA) associated with theselected beam. The selected TA may be one of the first TA and the secondTA. In an example, the wireless device may measure a first RSRP and/or afirst RSRQ of the first beam, and/or measure a second RSRP and/or asecond RSRQ of the second beam. In an example, the determining the oneof the first beam and the second beam as the selected beam may comprisedetermining the one of the first beam and the second beam based on atleast one of: the first RSRP and/or the first RSRP of the first beam(e.g., SS or CSI-RS); and/or the second RSRP and/or the second RSRQ ofthe second beam (e.g., SS or CSI-RS). In an example, if the first RSRPis equal to or larger than a power value and/or if the first RSRQ isequal to or larger than a power value, the wireless device may selectthe first beam as the selected beam. In an example, if the second RSRPis equal to or larger than a power value and/or if the second RSRQ isequal to or larger than a power value, the wireless device may selectthe second beam as the selected beam. In an example, if the first RSRPis larger than the second RSRP and/or if the first RSRQ is larger thanthe second RSRQ, the wireless device may select the first beam as theselected beam.

In an example, if the first beam is selected as the selected beam, thewireless device select, as the selected TA, the first TA that isindicated for at least one of: the first beam, the first TRP, the firstTAG, the first CORESET group, the first TCI state, the first QCL type,and/or the like. In an example, if the second beam is selected as theselected beam, the wireless device select, as the selected TA, thesecond TA that is indicated for at least one of: the second beam, thesecond TRP, the second TAG, the second CORESET group, the second TCIstate, the second QCL type, and/or the like.

In an example, the wireless device may transmit, based on the accessinformation, transport blocks (e.g., via PUSCH) based on the selected TAto access the first cell. In an example, the transmitting the transportblocks may comprise transmitting the transport blocks via a physicaluplink shared channel (PUSCH) associated with the selected beam. In anexample, the transmitting the transport blocks may comprise applying theselected TA when transmitting the transport blocks. In an example,before transmitting the transport blocks, the wireless device mayperform synchronization to the first cell and/or the first base stationbased on the selected TA. The wireless device may transmit the transportblock based on the synchronization. The wireless device may derive keysthat is specific to the first base station and/or the first cell, and/ormay configure selected security algorithms based on the keys to be usedin the first cell.

In an example, if the selected beam is the first beam, the wirelessdevice may send/transmit the transport block via the first resourceindicated by the access information. If the selected beam is the secondbeam, the wireless device may send/transmit the transport block via thesecond resource indicated by the access information. In an example, thewireless device may receive, from the first base station, a downlinkcontrol information (DCI) (e.g., via PDCCH of the first cell) indicatingan uplink grant resource (e.g., uplink grant) for the transport blocks.The transmitting the transport blocks may comprise transmitting thetransport blocks via the uplink grant resource.

In an example, the transport blocks, which is transmitted by thewireless device to access the first cell, may comprise an uplink RRCmessage (e.g., an RRC reconfiguration complete message, an RRCconnection reconfiguration complete message). The uplink RRC message maybe scrambled with and/or may comprise a C-RNTI of the wireless device atthe first cell. The first base station may confirm the handover based onreceiving the uplink RRC message (e.g., the RRC reconfiguration completemessage, an RRC connection reconfiguration complete message). In anexample, the transport blocks may further comprise an uplink bufferstatus report (BSR), uplink data, and/or the like. The first basestation may verify the C-RNTI. Based on the verification of the C-RNTIof the wireless device, the first base station may begin sending data tothe wireless device. The handover may be completed for the wirelessdevice when the wireless device receives a MAC CE indicating a UEcontention resolution identity from the first base station. The firstbase station may send, to the second base station and/or based onreceiving the uplink RRC message, a path switch request message to acore network node (e.g., the AMF, an MME, etc.) to inform that thewireless device has changed a cell and/or a base station.

In an example, as shown in FIG. 24 and/or FIG. 25 and/or FIG. 28 , awireless device may receive, from a second base station, a radioresource control (RRC) message comprising access information for a firstcell of a first base station. The access information may indicate afirst timing advance (TA) associated with a first beam of the first celland a second TA associated with a second beam of the first cell. Thewireless device may determine one of the first beam and the second beamas a selected beam. The wireless device may select a selected TA (e.g.,among the first TA and the second TA) associated with the selected beam.The selected TA may be one of the first TA and the second TA. Thewireless device may transmit transport blocks based on the selected TAto access the first cell.

In an example, the access information may indicate at least one of: afirst panel of the wireless device for transmission associated with thefirst beam; a second panel of the wireless device for transmissionassociated with the second beam; and/or the like. The wireless devicemay use the first panel of the wireless device to transmit the transportblocks in response to the selected beam being the first beam. Thewireless device may use the second panel of the wireless device totransmit the transport blocks in response to the selected beam being thesecond beam.

In an example, the first base station may be the second base station. Inan example, the second base station may be a master base station (e.g.,master node, MgNB, MeNB, M-node, etc.) serving a master cell group (MCG)of the wireless device. The first base station may be a secondary basestation (e.g., secondary node, SgNB, SeNB, S-node, etc.) serving asecondary cell group (SCG) of the wireless device. In an example, theRRC message may comprise at least one of: a handover command message; anRRC reconfiguration message; and/or the like.

In an example, the first cell may comprise the first beam and the secondbeam. The first beam and/or the second beam may be associated with atleast one of: a channel state information-reference signal (CSI-RS); asynchronization signal (SS); and/or the like. In an example, the firstbeam may be transmitted by a first transmission reception point (TRP).The second beam may be transmitted by a second TRP. In an example, thefirst beam may be transmitted by a first base station distributed unitof the first base station. The second beam may be transmitted by asecond base station distributed unit of the first base station.

In an example, the first TA and/or the second TA may comprise at leastone of: a zero TA (e.g., TA=0); a TA of a primary timing advance group(TAG) of a master cell group (MCG); a TA of a secondary TAG of a mastercell group (MCG); a TA of a primary TAG of a secondary cell group (SCG);a TA of a secondary TAG of a secondary cell group (SCG); and/or thelike. In an example, the access information may comprise at least oneof: a fist value of the first TA; and/or a second value of the secondTA. In an example, the access information may indicate for the first TAand/or the second TA at least one of: a TA is zero; a primary TAG of anMCG; a secondary TAG (e.g., a TAG identifier of the secondary TAG) of anMCG; a primary TAG of an SCG; and/or a secondary TAG (e.g., a TAGidentifier of the secondary TAG) of an SCG.

In an example, the access information may comprise first fields forfirst resources associated with the first beam. The first fields maycomprise at least one of: a first number of configured hybrid automaticrepeat request (HARQ) processes; a first uplink grant; a first uplinkscheduling interval; a first uplink starting subframe/slot/symbol;and/or the like. In an example, the access information may comprisesecond fields for second resources associated with the second beam. Thesecond fields may comprise at least one of: a second number ofconfigured hybrid automatic repeat request (HARQ) processes; a seconduplink grant; a second uplink scheduling interval; a second uplinkstarting subframe/slot/symbol; and/or the like. In an example, thetransmitting the transport blocks may comprise transmitting thetransport blocks via the first resources or the second resourcesassociated with the selected beam.

In an example, the wireless device may receive, from the first basestation, a downlink control information (DCI) indicating an uplink grantresource for the transport blocks. The transmitting the transport blocksmay comprise transmitting the transport blocks via the uplink grantresource.

In an example, the access information may comprise at least one of: abeam index of the first beam; an identifier of a first TRP associatedwith the first beam and/or the first TA; a group identifier of a firstcontrol resource set (CORESET) group associated with the first TRPand/or the first TA; an identifier of a first transmission configurationindication (TCI) state associated with the first TRP and/or the firstTA; and/or the like. In an example, the access information may compriseat least one of: a beam index of the second beam; an identifier of asecond TRP associated with the second beam and/or the second TA; a groupidentifier of a second CORESET group associated with the second TRPand/or the second TA; an identifier of a second TCI state associatedwith the second TRP and/or the second TA; and/or the like.

In an example, the access information may comprise at least one of: anidentifier of a first TAG associated with the first beam and/or thefirst TA; and/or an identifier of a second TAG associated with thesecond beam and/or the second TA. In an example, the first TAG or thesecond TAG may comprise at least one of: one or more cells; one or moreTRPs; one or more beams (e.g., SSB, CSI-RS beam); one or more CORESETgroups; one or more TCI states; and/or the like.

In an example, the access information may comprise random accessconfiguration parameters associated with at least one third beam (e.g.,SSB, CSI-RS) (e.g., The at least one third beam may comprise the firstbeam and/or the second beam) for the wireless device to access the firstcell. The random access configuration parameters may comprise at leastone of: a beam index; a random access preamble index (e.g., integervalue 0 to 63); at least one random access occasion (e.g., for CSI-RS);a reference signal received power (RSRP) value (e.g., threshold)indicating a range of received power (e.g., to perform a contention freerandom access procedure). In an example, the at least one third beam maybe transmitted by a third TRP.

In an example, the access information may comprise a power value for thewireless device to determine initiation of a random access using therandom access configuration parameters. The wireless device may comparethe power value with a received power of the first beam and/or thesecond beam for the initiation of the random access. In an example, theaccess information may comprise a time value for the wireless device todetermine initiation of a random access using the random accessconfiguration parameters. The wireless device may initiate the randomaccess in response to a time duration of the time value passing (e.g.,in response to expiry of the time duration) since/from/after the firstsignal (e.g., one of the transport blocks, PUSCH, random accesspreamble, etc.) transmission to the first base station. In an example, arandom access using the random access configuration parameters maycomprise at least one of: a contention-free random access; acontention-based random access; and/or the like.

In an example, the access information may be determined by at least oneof: the first base station (e.g., for a handover of the wireless device)and/or the second base station (e.g., for a secondary base stationaddition/modification of the wireless device).

In an example, the transmitting the transport blocks may comprisetransmitting the transport blocks via a physical uplink shared channel(PUSCH) associated with the selected beam. In an example, thedetermining the one of the first beam and the second beam as theselected beam may comprise determining the one of the first beam and thesecond beam based on at least one of: a first RSRP of the first beam(e.g., SS or CSI-RS); and/or a second RSRP of the second beam (e.g., SSor CSI-RS). In an example, the transmitting the transport blocks maycomprise applying the selected TA when transmitting the transportblocks.

In an example, the wireless device may receive, from the first basestation, at least one of: the first beam (e.g., SS or CSI-RS); thesecond beam (e.g., SS or CSI-RS); the at least one third beam; and/orthe like. In an example, the wireless device may send to the second basestation and based on the receiving the first beam (e.g., SS or CSI-RS)and/or the second beam (e.g., SS or CSI-RS), at least one measurementreport comprising measurement results of the first cell. The measurementresults may comprise at least one of: a first received power of thefirst beam (e.g., SS or CSI-RS); a first received quality of the firstbeam (e.g., SS or CSI-RS); a second received power of the second beam(e.g., SS or CSI-RS); a second received quality of the second beam(e.g., SS or CSI-RS); a third received power of the at least one thirdbeam (e.g., SS or CSI-RS); a third received quality of the at least onethird beam (e.g., SS or CSI-RS); and/or the like.

In an example, the second base station may determine, based on the atleast one measurement report, a handover of the wireless device to thefirst cell. In an example, the second base station may send, to thefirst base station, a handover request message for the handover of thewireless device. In an example, the second base station may receive,from the first base station, a handover request acknowledge messagecomprising the access information for the first cell. The RRC message(e.g., comprising the access information) may be based on the handoverrequest acknowledge message.

In an example, the second base station may determine, based on the atleast one measurement report, a secondary node configuration (e.g., asecondary node addition or modification) for the wireless device. In anexample, the second base station may send, to the first base station, aconfiguration request message (e.g., a secondary node addition requestmessage or a secondary node modification request message) for thesecondary node configuration for the wireless device. In an example, thesecond base station may receive, from the first base station, aconfiguration request acknowledge message comprising the accessinformation for the first cell. The RRC message (e.g., comprising theaccess information) may be based on the configuration requestacknowledge message. In an example, the secondary node configuration maycomprise at least one of: a secondary node addition; a secondary nodemodification; and/or the like. The secondary node configuration maycomprise configuring the first cell as an SCG for the wireless device.

In an example, as shown in FIG. 24 , a wireless device may receive, froma second base station, an RRC message comprising access information fora first cell of a first base station. The access information mayindicate a first TA associated with a first beam of the first cell and asecond TA associated with a second beam of the first cell. The wirelessdevice may determine a selected TA associated with a selected beam. Theselected beam may be one of the first beam and the second beam. Theselected TA may be one of the first timing advance and the second timingadvance. The wireless device may transmit transport blocks based on theselected timing advance to access the first cell.

In an example, as shown in FIG. 25 , a first base station may transmit afirst beam and a second beam via a first cell. The first base stationmay receive, from a second base station, a request message for ahandover (e.g., or a secondary node addition/modification) of a wirelessdevice to the first cell of the first base station. The first basestation may determine access information for the wireless device. Theaccess information may indicate a first TA associated with the firstbeam of the first cell and a second TA associated with the second beamof the first cell. The first base station may send, to the second basestation and in response to the request message, a request acknowledgemessage comprising the access information. The first base station mayreceive, from the wireless device, transport blocks based on one of thefirst timing advance or the second timing advance.

In an example, a second base station may receive, from a wirelessdevice, at least one measurement report comprising measurement resultsof a first cell. The second base station may determine, based on the atleast one measurement report, a handover (e.g., or a secondary nodeaddition/modification) of the wireless device to the first cell. Thesecond base station may send, to the first base station, a requestmessage for the handover (e.g., or a secondary nodeaddition/modification) of the wireless device. The second base stationmay receive, from the first base station, a request acknowledge messagecomprising access information for the first cell. The access informationmay indicate a first TA associated with the first beam of the first celland a second TA associated with the second beam of the first cell. Thesecond base station may send, to the wireless device, an RRC message(e.g., a handover command or an RRC reconfiguration message) comprisingthe access information.

In an example, a wireless device may receive, from a second basestation, a radio resource control message comprising access informationfor a first cell of a first base station. The access information mayindicate a first timing advance associated with a first beam of thefirst cell. The wireless device may determine/select the first beam toaccess the first cell. The wireless device may transmit, based on thedetermining the first beam, transport blocks based on the first timingadvance to access the first cell.

According to various embodiments, a device such as, for example, awireless device, off-network wireless device, a base station, and/or thelike, may comprise one or more processors and memory. The memory maystore instructions that, when executed by the one or more processors,cause the device to perform a series of actions. Embodiments of exampleactions are illustrated in the accompanying figures and specification.Features from various embodiments may be combined to create yet furtherembodiments.

FIG. 29 is a diagram of an aspect of an example embodiment of thepresent disclosure. At 2910, a wireless device may receive, from asecond base station, a radio resource control message comprising accessinformation for a handover to a first cell of a first base station. Theaccess information may indicate that a first timing advance of a firstbeam of the first cell is a timing advance of a first timing advancegroup of a secondary cell group of the wireless device and that a secondtiming advance of a second beam of the first cell is a timing advance ofa second timing advance group of the secondary cell group. At 2920, thewireless device may select, as a selected beam, one of the first beamand the second beam. At 2930, the wireless device may transmit transportblocks, via the selected beam of the first cell, using one of the firsttiming advance in response to the selected beam being the first beam andthe second timing advance in response to the selected beam being thesecond beam.

According to an example embodiment, the first base station may be thesecond base station. When the wireless device receives the radioresource control message, the second base station may be a master basestation serving a master cell group of the wireless device and/or thefirst base station may be a secondary base station serving the secondarycell group of the wireless device. The first beam may be transmitted bya first transmission reception point or a first base station distributedunit of the first base station. The second beam may be transmitted by asecond transmission reception point or a second base station distributedunit of the first base station. The first beam or the second beam may beassociated with a channel state information-reference signal. The firstbeam or the second beam may be associated with a synchronization signal.

According to an example embodiment, the first timing advance group orthe second timing advance group may be a primary timing advance group.The first timing advance group or the second timing advance group may bea secondary timing advance group. The access information may indicatethat a third timing advance of a third beam of the first cell is atiming advance of zero. The access information may indicate that a thirdtiming advance of a third beam of the first cell is a timing advance ofa primary timing advance group of a master cell group. The accessinformation may indicate that a third timing advance of a third beam ofthe first cell is a timing advance of a secondary timing advance groupof a master cell group. The access information may indicate that a thirdtiming advance of a third beam of the first cell is a timing advance ofa primary timing advance group of the secondary cell group. The accessinformation may indicate that a third timing advance of a third beam ofthe first cell is a timing advance of a secondary timing advance groupof the secondary cell group.

According to an example embodiment, the access information may indicatesa beam index of the first beam. The access information may indicates thefirst timing advance is for a first transmission reception point (TRP)associated with the first beam. The access information may indicates thefirst timing advance is for a first control resource set (CORESET) groupassociated with the first beam. The access information may indicates thefirst timing advance is for a first transmission configurationindication (TCI) state associated with the first beam. The accessinformation may indicates the first timing advance is for a third timingadvance group of the wireless device after completion of the handover.The access information may comprise a beam index of the second beam. Theaccess information may comprise the second timing advance is for asecond TRP associated with the second beam. The access information maycomprise the second timing advance is for a second CORESET groupassociated with the second beam. The access information may comprise thesecond timing advance is for a second TCI state associated with thesecond beam. The access information may comprise the second timingadvance is for a fourth timing advance group of the wireless deviceafter completion of the handover.

According to an example embodiment, the access information may comprisea time value indicating a time duration that the first timing advance orthe second timing advance may be valid for the handover. The selectingthe one of the first beam and the second beam may comprise selecting theone of the first beam and the second beam based on a first referencesignal received power of the first beam. The selecting the one of thefirst beam and the second beam may comprise selecting the one of thefirst beam and the second beam based on a second reference signalreceived power of the second beam.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in a wireless device, a base station, a radio environment, a network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, wireless device or network nodeconfigurations, traffic load, initial system set up, packet sizes,traffic characteristics, a combination of the above, and/or the like.When the one or more criteria are met, various example embodiments maybe applied. Therefore, it may be possible to implement exampleembodiments that selectively implement disclosed protocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). A base station may comprise multiple sectors. When thisdisclosure refers to a base station communicating with a plurality ofwireless devices, this disclosure may refer to a subset of the totalwireless devices in a coverage area. This disclosure may refer to, forexample, a plurality of wireless devices of a given LTE or 5G releasewith a given capability and in a given sector of the base station. Theplurality of wireless devices in this disclosure may refer to a selectedplurality of wireless devices, and/or a subset of total wireless devicesin a coverage area which perform according to disclosed methods, and/orthe like. There may be a plurality of base stations or a plurality ofwireless devices in a coverage area that may not comply with thedisclosed methods, for example, because those wireless devices or basestations perform based on older releases of LTE or 5G technology.

In this disclosure, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” Similarly, any termthat ends with the suffix “(s)” is to be interpreted as “at least one”and “one or more.” In this disclosure, the term “may” is to beinterpreted as “may, for example.” In other words, the term “may” isindicative that the phrase following the term “may” is an example of oneof a multitude of suitable possibilities that may, or may not, beemployed to one or more of the various embodiments.

If A and B are sets and every element of A is also an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B = {cell1,cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on”(or equally “based at least on”) is indicative that the phrase followingthe term “based on” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “in response to” (or equally “inresponse at least to”) is indicative that the phrase following thephrase “in response to” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “depending on” (or equally “depending atleast to”) is indicative that the phrase following the phrase “dependingon” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.The phrase “employing/using” (or equally “employing/using at least”) isindicative that the phrase following the phrase “employing/using” is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments.

The term configured may relate to the capacity of a device whether thedevice is in an operational or non-operational state. Configured mayalso refer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ornon-operational state. In other words, the hardware, software, firmware,registers, memory values, and/or the like may be “configured” within adevice, whether the device is in an operational or nonoperational state,to provide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics ormay be used to implement certain actions in the device, whether thedevice is in an operational or non-operational state

In this disclosure, various embodiments are disclosed. Limitations,features, and/or elements from the disclosed example embodiments may becombined to create further embodiments within the scope of thedisclosure.

In this disclosure, parameters (or equally called, fields, orInformation elements: IEs) may comprise one or more information objects,and an information object may comprise one or more other objects. Forexample, if parameter (IE) N comprises parameter (IE) M, and parameter(IE) M comprises parameter (IE) K, and parameter (IE) K comprisesparameter (information element) J. Then, for example, N comprises K, andN comprises J. In an example embodiment, when one or more messagescomprise a plurality of parameters, it implies that a parameter in theplurality of parameters is in at least one of the one or more messages,but does not have to be in each of the one or more messages.

Furthermore, many features presented above are described as beingoptional through the use of “may” or the use of parentheses. For thesake of brevity and legibility, the present disclosure does notexplicitly recite each and every permutation that may be obtained bychoosing from the set of optional features. However, the presentdisclosure is to be interpreted as explicitly disclosing all suchpermutations. For example, a system described as having three optionalfeatures may be embodied in seven different ways, namely with just oneof the three possible features, with any two of the three possiblefeatures or with all three of the three possible features.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an element thatperforms a defined function and has a defined interface to otherelements. The modules described in this disclosure may be implemented inhardware, software in combination with hardware, firmware, wetware (i.e.hardware with a biological element) or a combination thereof, all ofwhich may be behaviorally equivalent. For example, modules may beimplemented as a software routine written in a computer languageconfigured to be executed by a hardware machine (such as C, C++,Fortran, Java, Basic, Matlab or the like) or a modeling/simulationprogram such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript.Additionally, it may be possible to implement modules using physicalhardware that incorporates discrete or programmable analog, digitaland/or quantum hardware. Examples of programmable hardware comprise:computers, microcontrollers, microprocessors, application-specificintegrated circuits (ASICs); field programmable gate arrays (FPGAs); andcomplex programmable logic devices (CPLDs). Computers, microcontrollersand microprocessors are programmed using languages such as assembly, C,C++ or the like. FPGAs, ASICs and CPLDs are often programmed usinghardware description languages (HDL) such as VHSIC hardware descriptionlanguage (VHDL) or Verilog that configure connections between internalhardware modules with lesser functionality on a programmable device. Theabove mentioned technologies are often used in combination to achievethe result of a functional module.

The disclosure of this patent document incorporates material which issubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, for the limited purposes required by law, butotherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and detail can be made thereinwithout departing from the scope. In fact, after reading the abovedescription, it will be apparent to one skilled in the relevant art(s)how to implement alternative embodiments. Thus, the present embodimentsshould not be limited by any of the above described exemplaryembodiments.

In addition, it should be understood that any figures which highlightthe functionality and advantages, are presented for example purposesonly. The disclosed architecture is sufficiently flexible andconfigurable, such that it may be utilized in ways other than thatshown. For example, the actions listed in any flowchart may bere-ordered or only optionally used in some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable theU.S. Patent and Trademark Office and the public generally, andespecially the scientists, engineers and practitioners in the art whoare not familiar with patent or legal terms or phraseology, to determinequickly from a cursory inspection the nature and essence of thetechnical disclosure of the application. The Abstract of the Disclosureis not intended to be limiting as to the scope in any way.

Finally, it is the applicant’s intent that only claims that include theexpress language “means for” or “step for” be interpreted under 35U.S.C. 112. Claims that do not expressly include the phrase “means for”or “step for” are not to be interpreted under 35 U.S.C. 112.

What is claimed is:
 1. A method comprising: sending, by a second basestation to a wireless device, a radio resource control (RRC) messageindicating a handover to a cell, the RRC message indicating: a firsttiming advance of a first beam of the cell; and a second timing advanceof a second beam of the cell, wherein the first timing advance and thesecond timing advance are provided for beam selection by the wirelessdevice for transmission, via a selected beam of the first beam or thesecond beam, transport blocks using one of the first timing advance orthe second timing advance corresponding to the selected beam.
 2. Themethod of claim 1, wherein the handover is to a first base station. 3.The method of claim 2, wherein when the radio resource control messageis sent: the second base station is a master base station serving amaster cell group of the wireless device; and the first base station isa secondary base station serving the secondary cell group of thewireless device.
 4. The method of claim 1, wherein: the first beam istransmitted by a first transmission reception point or a first basestation distributed unit of a first base station; and the second beam istransmitted by a second transmission reception point or a second basestation distributed unit of the first base station.
 5. The method ofclaim 1, wherein the first beam or the second beam is associated with atleast one of: a channel state information-reference signal; or asynchronization signal.
 6. The method of claim 1, wherein: the firsttiming advance is for a first timing advance group; the second timingadvance is for a second timing advance group; and the first timingadvance group or the second timing advance group is at least one of: aprimary timing advance group; or a secondary timing advance group. 7.The method of claim 6, wherein the radio resource control messageindicates that a third timing advance of a third beam of the first cellis a timing advance of at least one of: zero; a primary timing advancegroup of a master cell group; a secondary timing advance group of amaster cell group; a primary timing advance group of the secondary cellgroup; or a secondary timing advance group of the secondary cell group.8. The method of claim 6, wherein the radio resource control messageindicates at least one of: a beam index of the first beam; the firsttiming advance is for a first transmission reception point (TRP)associated with the first beam; the first timing advance is for a firstcontrol resource set (CORESET) group associated with the first beam; thefirst timing advance is for a first transmission configurationindication (TCI) state associated with the first beam; the first timingadvance is for a third timing advance group of the wireless device aftercompletion of the handover; a beam index of the second beam; the secondtiming advance is for a second TRP associated with the second beam; thesecond timing advance is for a second CORESET group associated with thesecond beam; the second timing advance is for a second TCI stateassociated with the second beam; or the second timing advance is for afourth timing advance group of the wireless device after completion ofthe handover.
 9. The method of claim 1, wherein the radio resourcecontrol message comprises a time value indicating a time duration thatthe first timing advance or the second timing advance is valid for thehandover.
 10. The method of claim 1, wherein the selecting the one ofthe first beam and the second beam comprises selecting the one of thefirst beam and the second beam based on at least one of: a firstreference signal received power of the first beam; or a second referencesignal received power of the second beam.
 11. A second base stationcomprising: one or more processors; and memory storing instructionsthat, when executed by the one or more processors, cause the second basestation to: send, to a wireless device, a radio resource control (RRC)message indicating a handover to a cell, the RRC message indicating: afirst timing advance of a first beam of the cell; and a second timingadvance of a second beam of the cell, wherein the first timing advanceand the second timing advance are provided for beam selection by thewireless device for transmission, via a selected beam of the first beamor the second beam, transport blocks using one of the first timingadvance or the second timing advance corresponding to the selected beam.12. The second base station of claim 11, wherein the handover is to afirst base station and the RRC message is received from a second basestation.
 13. The second base station of claim 12, wherein when receivingthe radio resource control message: the second base station is a masterbase station serving a master cell group of the wireless device; and thefirst base station is a secondary base station serving the secondarycell group of the wireless device.
 14. The second base station of claim11, wherein: the first beam is transmitted by a first transmissionreception point or a first base station distributed unit of a first basestation; and the second beam is transmitted by a second transmissionreception point or a second base station distributed unit of the firstbase station.
 15. The second base station of claim 11, wherein the firstbeam or the second beam is associated with at least one of: a channelstate information-reference signal; or a synchronization signal.
 16. Thesecond base station of claim 11, wherein: the first timing advance isfor a first timing advance group; the second timing advance is for asecond timing advance group; and the first timing advance group or thesecond timing advance group is at least one of: a primary timing advancegroup; or a secondary timing advance group.
 17. The second base stationof claim 16, wherein the radio resource control message indicates that athird timing advance of a third beam of the first cell is a timingadvance of at least one of: zero; a primary timing advance group of amaster cell group; a secondary timing advance group of a master cellgroup; a primary timing advance group of the secondary cell group; or asecondary timing advance group of the secondary cell group.
 18. Thesecond base station of claim 16, wherein the radio resource controlmessage indicates at least one of: a beam index of the first beam; thefirst timing advance is for a first transmission reception point (TRP)associated with the first beam; the first timing advance is for a firstcontrol resource set (CORESET) group associated with the first beam; thefirst timing advance is for a first transmission configurationindication (TCI) state associated with the first beam; the first timingadvance is for a third timing advance group of the wireless device aftercompletion of the handover; a beam index of the second beam; the secondtiming advance is for a second TRP associated with the second beam; thesecond timing advance is for a second CORESET group associated with thesecond beam; the second timing advance is for a second TCI stateassociated with the second beam; or the second timing advance is for afourth timing advance group of the wireless device after completion ofthe handover.
 19. The second base station of claim 11, wherein the radioresource control message comprises a time value indicating a timeduration that the first timing advance or the second timing advance isvalid for the handover.
 20. A non-transitory computer-readable mediumcomprising instructions that, when executed by one or more processors,cause the one or more processors to perform: sending, by a second basestation to a wireless device, a radio resource control (RRC) messageindicating a handover to a cell, the RRC message indicating: a firsttiming advance of a first beam of the cell; and a second timing advanceof a second beam of the cell, wherein the first timing advance and thesecond timing advance are provided for beam selection by the wirelessdevice for transmission, via a selected beam of the first beam or thesecond beam, transport blocks using one of the first timing advance orthe second timing advance corresponding to the selected beam.